Gemstone optimization methods and typical characteristics
Identification Characteristics of Common Natural and Synthetic Gemstones
Johdanto:
Explore the definitive resource for jewelry aficionados and professionals alike. Dive into the world of gemstone enhancement with detailed methods and characteristics for diamonds, rubies, sapphires, and other precious stones. Learn to distinguish natural gems through their unique identification features, including color, chemical composition, and hardness. Stay ahead in the market by understanding synthetic gemstones and their production methods. This guide is tailored for jewelry stores, studios, brands, retailers, designers, e-commerce sellers, and drop shippers seeking to curate authentic and enhanced gem collections. Enhance your expertise with insights on laser drilling, irradiation, heat treatment, and other optimization processes. Master the nuances of gemstone identification with our comprehensive sections on natural and synthetic characteristics, ensuring you offer only the finest quality to your clientele, including custom-made pieces for celebrities.
Sisällysluettelo
Section I Common gemstone optimization methods and typical characteristics
| Jewelry and gemstone names | Optimization treatment methods | Kategoriat | Processing effect | Typical identification characteristics |
|---|---|---|---|---|
| Timantti | Laser Drilling | Treatment | Improve the clarity of diamonds | Laser holes can be observed under magnification |
| Filling | Treatment | Improve the durability and appearance of diamonds | Flashing effect under different fields of view (bright or dark) | |
| Irradiation | Treatment | Change color | Characteristic absorption lines of different colors | |
| Coating | Treatment | Change in color or appearance | Low surface hardness, with scratches and wear | |
| High temperature and high pressure | Treatment | Improve or change color | GE-POL logo or 529nm fluorescence spectrum line and 986nm absorption spectrum line | |
| Ruby | Heat treatment | Optimization | Improve color, remove blue-purple tones | The crystalline package has some melting and other heat treatment features |
| Dyeing treatment | Treatment | Change or improve color brightness | Magnified inspection of the dye distribution along the gemstone's fissures | |
| Filling (colorless oil or wax) | Optimization | Improving the durability of the gemstone | Internal sparkling effect, lower transparency at the fissures | |
| Filling (colored oil or wax) | Treatment | Improving the color and durability of the gemstone | There are internal sparkling effects, and the color distribution along the fissures is magnified. | |
| Diffusion | Treatment | Improve the color of the gemstone or create a starlight effect | Uneven distribution of color inside and outside, with heat treatment characteristics |
| Jewelry and gemstone names | Optimization treatment methods | Kategoriat | Processing effect | Typical identification characteristics |
|---|---|---|---|---|
| Sapphire | Heat treatment | Optimization | Change or improve appearance | Crystalline inclusions have partial melting and other heat treatment characteristics |
| Dyeing | Treatment | Improve or change color | Magnified inspection of dye distribution along fissures | |
| Filling (colorless wax or oil) | Optimization | Improve durability, conceal fissures | Internal shimmering effect, lower transparency at crack edges | |
| Irradiation | Treatment | Changing color | Color instability, returns to original color after heating | |
| Diffusion | Treatment | Change color or produce starlight effects | Surface diffusion: uneven surface color, lighter internal color; body diffusion: color penetrates into the interior, uniform surface color | |
| Cat's eye | Irradiation | Treatment | Improve color or eyeline | Conventional gem testing methods cannot determine |
| Emerald | Filling (colorless oil or wax) | Optimization | Improve durability | There is a sparkling effect internally, and the transparency is lower at the fissures |
| Filling (colored oil or wax) | Treatment | Improve gem color and durability | Internal sparkling effect, magnified inspection of color distribution along fissures | |
| Dyeing | Treatment | Change or improve color | Magnified inspection of dye distribution along fissures, uneven internal color | |
| Coating | Treatment | Improve or change color and luster | Due to the low hardness of the coated surface, there are scratches on the surface, and magnified inspection can observe that parts of the film often peel off. | |
| Aquamarine | Heat treatment | Optimization | Improve or change color | There are some melted inclusions inside. |
| Dyeing | Treatment | Improve or change color | Magnified inspection shows that the dye is distributed along the fissures, and the internal color is uneven. | |
| Filling (colorless oil or wax) | Optimization | Improve durability | There is a flashing effect inside, and the transparency is lower at the fissures. | |
| Filling (colored oil or wax) | Treatment | Improve the color and durability of the gemstone | Internal sparkling effect, magnifying inspection of color distribution along fissures | |
| Irradiation | Treatment | Changing color | Conventional gem testing methods cannot determine | |
| Beryl | Heat treatment | Optimization | Improve color | The heat treatment temperature is relatively low, making it difficult to identify |
| Filling (colorless oil or wax) | Optimization | Improve durability | There is a flashing effect inside, and the transparency is lower at the fissures | |
| Filling (colored oil or wax) | Treatment | Improve gem color and durability | There is a shimmering effect inside, and the color distribution along the fissures is examined under magnification | |
| Irradiation | Treatment | Changing color | Conventional gem testing methods cannot determine | |
| Coating | Treatment | Change in color or luster | Low surface hardness, often has scratches, wear, and other appearance features | |
| Turmaliini | Heat treatment | Optimization | Improve color | There may be some melting in the internal packaging |
| Filling (colorless oil or wax) | Optimization | Improve durability | There is a sparkling effect inside, and the transparency is lower at the fissures | |
| Filling (colored oil or wax) | Treatment | Improve gem color and durability | Internal glitter effect, magnified inspection of color distribution along fissures | |
| Dyeing | Treatment | Change the color of the gemstone | Magnify and examine the distribution of the dye along the fissures; internal color is uneven | |
| Irradiation | Treatment | Changing color | Good stability; conventional tests cannot determine | |
| Coating | Treatment | Change in color or luster | Low surface hardness, often has scratches, wear, and other appearance features | |
| Zirkoni | Heat treatment | Optimization | Change or color | Low heat treatment temperature, difficult to identify |
| Irradiation | Treatment | Changing color | Different colors have characteristic absorption lines |
| Jewelry and gemstone names | Optimization treatment methods | Kategoriat | Processing effect | Typical identification characteristics |
|---|---|---|---|---|
| Spinelli | Filling (colorless oil or wax) | Optimization | Improve durability | Internal flashing effect, lower transparency at fissures |
| Filling (colored oil or wax) | Treatment | Improving the color and durability of gemstones | Internal flashing effect, magnified inspection of color distribution along fissures | |
| Dyeing | Treatment | Change color | Uneven color distribution, magnified inspection of color distribution along fissures | |
| Diffusion | Treatment | Improve or change color | The color is limited to the surface, the internal color is light | |
| Topaz | Dyeing | Treatment | Change color | The color distribution is uneven, magnify to check the color along the fissures |
| Diffusion | Treatment | Change color | The color is limited to the surface, the internal color is light, and the external color is dark | |
| Irradiation | Treatment | Change color | Blue topaz is common and has good stability | |
| Coating | Treatment | Improve color or luster | Low surface hardness, with scratches and wear | |
| Granaatti | Heat treatment | Optimization | Change or improve color | There is partial melting in the internal package. |
| Filling (colorless oil or wax) | Optimization | Improve durability | There is a flashing effect inside, and the transparency is lower at the fissures. | |
| Filling (colored oil or wax) | Treatment | Improve the color and durability of the gemstone | There are internal flashing effects, and the color distribution along the fissures is magnified. | |
| Kristalli | Heat treatment | Optimization | Change or improve color | The heat treatment temperature is lower, making it difficult to identify |
| Irradiation | Optimization | Changing color | Conventional identification instruments cannot distinguish | |
| Filling (colorless oil or wax) | Optimization | Improve durability | There is a flashing effect inside, and the transparency at the fissures is relatively low | |
| Filling (colored oil or wax) | Treatment | Improve gem color and durability | Internal glitter effect, magnified inspection of color distribution along fissures | |
| Dyeing | Treatment | Change gem color | Uneven color distribution, magnified inspection of color distribution along fissures | |
| Coating | Treatment | Change color, luster, etc. | Low surface hardness, with scratches and wear | |
| Feldspar | Filling (colorless oil or wax) | Optimization | Improve durability | Internal flashing effect, lower transparency at fissures |
| Filling (colored oil or wax) | Treatment | Improve gemstone color and durability | Internal flashing effect, magnifying inspection of color distribution along fissures | |
| Coating | Treatment | Change or improve color and luster | Low surface hardness, with scratches, wear, etc. | |
| Diffusion | Treatment | Changing color | Color limited to the surface, light internal color, dark external color | |
| Irradiation | Treatment | Changing color | Color stable, cannot be identified by conventional instruments | |
| Scapolite | Irradiation | Treatment | Changing color | Color stable, cannot be identified by conventional instruments |
| Tanzanite | Heat treatment | Optimization | Changing color | Color stable, vibrant blue-purple |
| Coating | Treatment | Change color or luster | Low surface hardness, with scratches and wear, high content of trace metal elements | |
| Spodumene | Irradiation | Treatment | Changing color | Color stable, cannot be identified by conventional instrument |
| Andalusite | Heat treatment | Optimization | Improve color | Color stable, cannot be identified by conventional instruments |
| Jewelry and gemstone names | Optimization treatment methods | Kategoriat | Processing effect | Typical identification characteristics |
|---|---|---|---|---|
| Kyanite | Dyeing | Treatment | Change or improve color | Uneven color distribution, magnify to check the distribution of the dye along the fissures |
| Filling (colorless oil or wax) | Optimization | Improve durability | Internal sparkling effect, lower transparency at the fissures | |
| Filling (colored oil or wax) | Treatment | Improve gem color and durability | Internal glitter effect, magnified inspection of color distribution along fissures | |
| Calcite | Dyeing | Treatment | Change or improve color | Uneven color distribution, magnified inspection of dye distribution along fissures |
| Filling (colorless oil or wax) | Optimization | Improve durability | Internal shimmering effect, lower transparency at fissures | |
| Filling (colored oil or wax) | Treatment | Improve gemstone color and durability | There is a flash effect inside, magnifying the inspection of color distribution along the fissures. | |
| Irradiation | Treatment | Change color | Color is stable, cannot be identified by conventional instruments. | |
| Euclase | Irradiation | Treatment | Change color | Color is stable, cannot be identified by conventional instruments. |
| Jade | Heat treatment | Optimization | Improve or change color | The color is stable, the coloring principle is the same as that of natural jade, and identification is not necessary. |
| Filling (colorless oil or wax) | Optimization | Improve durability | There is a flashing effect inside, and the transparency is lower at the fissures. | |
| Filling (colored oil or wax) | Treatment | Improve gemstone color and durability. | There is a flashing effect inside; magnified inspection shows color distribution along the fissures. | |
| Bleaching, filling | Treatment | Change the color to improve durability. | The color is clean and free of impurities, with a flashing effect at the filling | |
| Dyeing | Treatment | Changing color | Uneven color distribution, dye distributed along fissures, colorless roots | |
| Coating | Treatment | Change in color or luster | Low surface hardness, weak luster, with scratches | |
| Nefriitti | Filling (colorless oil or wax) | Optimization | Improve durability | There are internal sparkling effects, and the transparency is lower at the fissures. |
| Filling (colored oil or wax) | Treatment | Improve gemstone color and durability. | There are internal sparkling effects, and the color distribution along the fissures is magnified. | |
| Dyeing | Treatment | Change color | The color distribution is uneven, and the dye is distributed along the fissures. | |
| Opaali | Filling (colorless oil or wax) | Optimization | Improve durability | There is a sparkling effect internally, and the transparency is lower at the fissures |
| Filling (colored oil or wax) | Treatment | Improving gemstone color and durability | Internal sparkling effect, magnifying inspection of color distribution along fissures | |
| Dyeing | Treatment | Changing color | Common black opal, color distributed along the fissures | |
| Coating | Treatment | Change in color and luster | Surface has scratches and wear, highlighting the play of color | |
| Bonding | Treatment | Change in color and luster | Two-layer stone or three-layer stone, observe the bubbles in the seams and the differences in color and luster of different materials | |
| Chalcedony (Agate) | Heat treatment | Optimization | Improve or change color | Color stable, cannot be identified by conventional instruments |
| Filling (colorless oil or wax) | Optimization | Improve durability | There is a shimmering effect inside, and the transparency is lower at the fissures. | |
| Filling (colored oil or wax) | Treatment | Improve gemstone color and durability. | There is a shimmering effect inside, and the color distribution along the fissures is examined under magnification | |
| Dyeing | Optimization | Change color | The color is vivid, unevenly distributed, and the dye can be seen along the fissures under magnification. |
| Jewelry and gemstone names | Optimization treatment methods | Kategoriat | Processing effect | Typical identification characteristics |
|---|---|---|---|---|
| Quartzite Jade | Dyeing | Treatment | Change color | The color distribution is uneven, and upon magnification, the dye appears to be distributed in a mesh pattern. |
| Bleaching, filling | Treatment | Improving color and durability | The color is clean and free of impurities, with a sparkling effect in the filled areas | |
| Serpentine | Filling (colorless oil or wax) | Optimization | Improve durability | Internal shimmering effect, lower transparency at fissures |
| Filling (colored oil or wax) | Treatment | Improve gem color and durability | Internal sparkling effect, magnified inspection of color distribution along fissures | |
| Dyeing | Optimization | Change color | Vivid color, uneven distribution, visible dye distribution along fissures under magnification | |
| Turkoosi | Filling (colorless oil or wax) | Optimization | Improve durability | There are flashing effects inside, and the transparency is lower at the fissures. |
| Filling (colored oil or wax) | Treatment | Improve the color and durability of the gemstone. | There are flashing effects inside, magnified inspection shows color distribution along the fissures, with color distribution being more obvious at the iron lines. | |
| Dyeing | Treatment | Change color | The color is vivid and unevenly distributed, with visible dye distribution along the fissures upon magnified inspection. | |
| Density optimization | Optimization | Improve durability and appearance | Good stability, no need for identification (should include notes) | |
| Lapis lazuli | Filling (colorless oil or wax) | Optimization | Improve durability | Internal flash effect, lower transparency at fissures |
| Filling (colored oil or wax) | Treatment | Improving gemstone color and durability | Internal sparkling effect, magnifying inspection of color distribution along fissures | |
| Dyeing | Treatment | Changing color | Vivid color, uneven distribution, dye visible along fissures under magnification | |
| Malakiitti | Filling (colorless oil or wax) | Optimization | Improve durability | There is a flashing effect inside, and the transparency is lower at the fissures. |
| Filling (colored oil or wax) | Treatment | Improving gemstone color and durability | There is a flashing effect inside, and the color distribution along the fissures is examined under magnification. | |
| Marble | Filling (colorless oil or wax) | Optimization | Improve durability | There is a flashing effect inside, and the transparency is lower at the fissures. |
| Filling (colored oil or wax) | Treatment | Improve gemstone color and durability. | Internal sparkling effect, magnifying inspection of color distribution along fissures | |
| Dyeing | Treatment | Changing color | The color is vivid and unevenly distributed; under magnification, the dye can be seen distributed along the fissures. | |
| Coating | Treatment | Change in color or luster | The surface and internal colors are inconsistent, with scratches and wear. | |
| Rodokrosiitti | Filling (colorless oil or wax) | Optimization | Improve durability | There is a shimmering effect inside, and the transparency is lower at the fissures. |
| Filling (colored oil or wax) | Treatment | Improving gemstone color and durability | Internal sparkling effect, magnifying inspection of color distribution along fissures | |
| Talc | Dyeing | Treatment | Changing color | The color is vivid and unevenly distributed, with visible dye along the fissures under magnification. |
| Coating | Treatment | Change in color or luster | Inconsistent surface and internal colors, with scratches and wear |
| Jewelry and gemstone names | Optimization treatment methods | Kategoriat | Processing effect | Typical identification characteristics |
|---|---|---|---|---|
| Fluorite | Heat treatment | Optimization | Improve or Change Color | Color Stability, Cannot Be Identified by Conventional Instruments |
| Filling (colorless oil or wax) | Optimization | Improve durability | Internal flash effect, lower transparency at fissures | |
| Filling (colored oil or wax) | Treatment | Improve gemstone color and durability | There are flash effects inside, magnifying the color distribution along the fissures. | |
| Coating | Treatment | Change in color or luster | Inconsistency between surface and internal colors, with scratches and wear | |
| Irradiation | Treatment | Change color | Color is stable, cannot be identified by conventional instruments | |
| Natural Pearls | Bleaching | Optimization | Improve color and other appearances | Color is stable, no identification needed |
| Dyeing | Treatment | Change color | Color is vivid, gloss is weak, surface color is deep at the pearl hole, internal color is light | |
| Cultured pearls (pearls) | Bleaching | Optimization | Improving color and appearance | Color stability, no need for identification |
| Dyeing | Treatment | Change color | Vivid color, weak gloss, surface color deep at the bead holes, internal color light | |
| Irradiation | Treatment | Changing color | The color can penetrate deeply, with a uniform surface color and a strong metallic luster. | |
| Coral | Bleaching | Optimization | Improve color and other appearances. | Color is stable, no need for identification. |
| Filling (colorless oil or wax) | Optimization | Improve durability | There is a sparkling effect inside, with lower transparency at the fissures | |
| Filling (colored oil or wax) | Treatment | Improving gemstone color and durability | There is a flash effect inside, magnifying the inspection of color distribution along the fissures. | |
| Coating | Treatment | Improve or change color and luster. | The surface and internal colors are inconsistent, with scratches and wear, and the surface luster is strong. | |
| Dyeing | Treatment | Changing color | The color is vivid, with the dye distributed along the fissures | |
| Amber | Pressure clearing | Optimization | Improve transparency | Internally clean, can be sold as a natural product |
| Roasting color | Optimization | Change or improve color | Often has a localized fired color, stable in florescence | |
| Heat treatment | Optimization | Improve transparency | Common internal lily-shaped inclusions | |
| Recreate | Treatment | Compressing the powdered debris into large particle | Granular structure, with visible "blood streaks" inside, and a strong luster. | |
| Dyeing | Treatment | Changing color | Vivid color, uneven distribution, with color concentrated in fissures or pits. | |
| Coating | Treatment | Change in color, luster, and other appearances. | The membrane layer is relatively thin, with parts often peeling off the surface, and bubbles may sometimes be seen at the junction between the membrane and the amber surface |
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Section II Identification Characteristics of Common Natural Gemstones
| Jalokiven nimi | Väri | Kemiallinen koostumus | Taitekerroin | Suhteellinen tiheys | Kovuus | Dispersion value | UV fluorescence characterization (LW, SW) | Magnified inspection and other features | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Timantti | None - light yellow, blue, green, red, black, etc. | C, with small amounts of N, B, H | 2.417 | 3.52 | 10 | 0.044 | LW: None - strong blue, yellow fluorescence; SW: None - medium blue, yellow | Light-dark crystalline inclusion, plumes, clouds, triangular thin-sectioned bi-crystals, growth lines, primitive crystal faces, etc. Thermally conductive, with 415nm, 453nm, and 478nm absorption lines, Type II b blue diamonds are electrically conductive. | ||
| Zirkoni | Low type Medium type High type | Colorless and blue, yellow, green, brown, purple, black, etc. | ZrSiO4 | 1.810~1.984 | 3.90 ~4.80 | 6~7.5 | 0.038 | LW: No-medium blue, green, green-yellow and orange fluorescence; SW: Weak fluorescence | Mineral inclusions and healed fissures, surface scratches, and abrasions are common, and the rear faceted prisms are obvious, with more than 2~40 absorption lines visible, with 653.5nm characteristic absorption lines. | |
| Ruby | Medium-Deep Red | Al2O3 | 1.762 -1.770 | 4.00 | 9 | 0.018 | Weak-strong red fluorescence; the higher the chromium content, the stronger the fluorescence, the higher the Fe content, the weaker the fluorescence. | Crystalline inclusions, gas-liquid two-phase inclusions, fingerprint inclusions, etc., flat growth texture and color band, typical chromium absorption spectra: 694nm, 692nm, 668nm, 659nm absorption lines, 620-540nm absorption band, 476nm, 475nm strong absorption lines, 468nm weak absorption lines, violet region of the whole absorption. | ||
| Sapphire | Colorless and Blue, Pink, Yellow, Black, Green and gray, etc. | Al2O3 | No - weak LW: Weak - strong Red fluorescence; SW: Weak-medium red fluorescence, strong fluorescence in chromium-ionized stones | Crystalline inclusions, gas-liquid inclusions, and fingerprint inclusions with flat, angular growth textures and color bands, some of which have starburst and color change effects. Strong iridescent, blue, green, and yellow sapphires have characteristic absorption spectra: 450nm absorption band or 450nm, 460nm, and 470nm absorption lines. | ||||||
| Granaatti | Aluminum Series | Pyrope | Orange, Red | Mg2Al2(SiO4)3 | 1.714- 1.742 | 3.78 | 7~8 | Demantoid (0.057)Other varieties are lower(0.022- 2.027) | None; some colorless, light yellow, and light green grossular show weak orange-yellow fluorescence | Needle-like inclusion, irregular rounded crystalline inclusion, 564nm broad absorption band |
| Almandiini | Deep Red, Purple | Fe2Al2(SiO4)3 | 1.76-1.82 | 4.05 | Needle-like inclusion, crystalline inclusion, etc., 504nm, 520nm, 573nm strong absorption bands | |||||
| Spessartine | Orange-orange-red | Mn2Al2(SiO4)3 | 1.81 | 4.15 | Irregular rounded crystalline inclusion, 410nm, 420nm, 430nm absorption lines | |||||
| Calcium series | Grossular | Green, yellow, orange-red | Ca2Al2(SiO4)3 | 1.740 | 3.61 | Short columns or rounded crystalline envelopes, heat wave effec | ||||
| Andradite | Yellow, green, brown | Ca2Fe2(SiO4)3 | 1.888 | 3.84 | Characteristic “ponytail” envelope, 440 nm absorption band | |||||
| Uvarovite | Vihreä | Ca2Cr2(SiO4)3 | 1.850 | 3.75 | Smaller particles that turn red in the Charles filter | |||||
| Jalokiven nimi | Väri | Kemiallinen koostumus | Taitekerroin | Suhteellinen tiheys | Kovuus | Dispersion value | UV fluorescence characterization (LW, SW) | Magnified inspection and other features |
|---|---|---|---|---|---|---|---|---|
| Chrysoberyl | Light yellow, yellow, green and tawny | BeAl2O4 | 1.746 - 1.755 | 3.73 | 8-8.5 | 0.015 | None; some yellow and yellow-green chrysoberyl’s are weakly fluorescent | Fingerprints, fenestrations, filamentous inclusions, flat bands, bicrystalline, and stepped growth surfaces. Tricolor weakly-medium: yellow/green/brown, with a strong absorption band at 445nm. |
| Cat's eye | Yellow, yellow-green, gray-green, maroon | Weak to medium purplish red fluorescence | Many parallel-arranged filamentous inclusions, fingerprint inclusions, and negative crystals exist. Cat's eye effect, weak trichromatic, with a strong absorption band at 445nm. | |||||
| Alexandrite | Daylight: green, yellow-green; Under incandescent light: orange-red, maroon | Weak-medium purplish-red fluorescence, orange fluorescence under cathode rays | Fingerprint inclusions, filamentous inclusions, color change effect, cat's eye effect. Strong trichromatic: green/orange-yellow/purple-red; red zone 680nm, 678nm strong absorption line, 665nm, 655nm, 645nm weak absorption line, yellow-green zone 580~630nm bah-hopping absorption band, blue zone 476nm, 476nm, 468nm weak absorption line, violet zone full absorption. | |||||
| Hydrogrossular | Green, yellow, red | Ca3Al2(SiO4)3-x (VOI)4x | 1.72 | 3.47 | 7 | - | Ei ole | Fine-grained cryptocrystalline structure, black punctate inclusions, reddish color in Charles filter, dark green with full absorption below 460nm. |
| Spinelli | Colorless, red, blue, yellow, purple, etc. | MgAl2O4 | 1.718 | 3.60 | 8 | 0.020 | Light red, red spinel: weak-moderate red fluorescence; green: no-moderate orange fluorescence | Octahedral negative crystal envelope, red with 685nm. 684nm bow though absorption lines, 656nm weak absorption band, 595-490nm strong absorption band, blue, purple with 460nm strong absorption band. |
| Malakiitti | Blue-green, green | Cu2CO3(VOI)2 | 1.655- 1.909 | 3.54-4.1 | 3.5-4 | - | Ei ole | Striated, concentric ring structure, blistering in hydrochloric acid. |
| Oliviini | Yellowish green, green | (Mg,Fe)SiO4 | 1.654- 1.690 | 3.34 | 6.5-7 | 0.020 | Ei ole | Disk-shaped gas-liquid two-phase inclusion, dark mineral inclusion, negative crystal, with 453nm, 477nm, and 497nm strong absorption. |
| Jadeiitti | White, green, red, purple, gray, black, etc | NaAlSi2O6 | 1.66 | 3.34 | 6.5-7 | - | Ei ole | Dot and flake flashes (emerald), interwoven fiber structure with 437nm absorption lines, chromogenic with 630nm, 660nm, 690nm absorption lines. |
| Turmaliini | Variety of colors, can be two-color or multi-color | AB3C6(BO3)3 Si6O18(OH, F)4 | 1.624- 1.644 | 3.06 | 7~8 | 0.017 | Generally absent, pink, red Chromium-containing: weakly red to purple | Gas-liquid, tubular, and linear inclusion with longitudinal lines on the crystal column surface. Pink, red, green zone broad absorption band, sometimes visible 525nm narrow band, 451nm, 458nm absorption line; blue-green, red zone absorption, 498nm strong absorption band. |
| Jalokiven nimi | Väri | Kemiallinen koostumus | Taitekerroin | Suhteellinen tiheys | Kovuus | Dispersion value | UV fluorescence characterization (LW, SW) | Magnified inspection and other features |
|---|---|---|---|---|---|---|---|---|
| Topaz | White, yellow, blue, green, etc. | Al2SiO4(F,OH)2 | 1.619- 1.627 | 3.53 | 8 | 0.014 | None - weak orange-yellow, yellow-green, with chromium: orange fluorescence | Two or three-phase inclusions, inclusions of two or more immiscible liquids, mineral inclusions, negative crystals, etc. Longitudinal lines on the surface of the raw stone |
| Apatiitti | Colorless, yellow, green, purple, and blue, etc. | Ca5(PO4)3 (F, OH, Cl) | 1.634- 1.638 | 3.18 | 5-5.5 | - | None, often produces phosphorescence when heated | Gas-liquid inclusions, mineral inclusions, etc., yellow, colorless, and cat's-eye effect gemstones with 580nm absorption bilinear, blue with strong polychromatic |
| Andalusite | Yellowish green, yellowish brown, green, pink | AI2SiO5 | 1.634- 1.643 | 3.17 | 7-7.5 | - | Ei ole | Needle-like inclusions, vacuolate variant with black carbon inclusions in cross-distribution, strong trichromatic: brown-yellow-green/brown-orange/maroon red |
| Euclase | Colorless, light green, light blue | BeAISiO4(VOI) | 1.652- 1.671 | 3.08 | 7~8 | 0.016 | Ei ole | Red and blue plate-like inclusions and ring bands, strong polychromatic, with 468nm and 455nm absorption bands, absorption in the green and red areas |
| Prehnite | Colorless, light yellow, light green | Ca2AI(AISi3O10) (OH)2 | 1.63 | 2.8-2.95 | 6-6.5 | - | Ei ole | The fibrous structure is arranged in a radial pattern, with a weak absorption band at 438 nm, red under the Charles filter. |
| Turkoosi | Sky blue, blue, green. | CUAI6(PO4)4 (VOI)8•5H2O | 1.61 | 2.76 | 5~6 | - | LW:None - weak yellowish green, blue; SW:None | Often speckled structure, reticulated brown matrix |
| Nefriitti | Colorless, green, yellow, gray, black, etc. | Ca2(Mg, Fe)5 Si8O22(VOI)2 | 1.62 | 2.95 | 6-6.5 | - | Ei ole | Fibrous interwoven structure, black envelope, and high-quality green can be seen in the red region fuzzy absorption lines |
| Rodokrosiitti | Pink, often with white, gray, and brown stripes | MnCO3 | 1.597- 1.817 | 3.60 | 3~5 | - | Ei ole | Striated and layered texture, blistering in hydrochloric acid, transparent stone with medium to strong polychromic: orange/red. |
| Emerald | Green, blue-green, yellow-green | Be3Al2(Si6O18) | 1.577 〜 1.583 | 2.72 | 7.5-8 | 0.014 | None - weak: dark red, weak red fluorescence under X-rays | Fissure development, gas-liquid two-phase inclusions, three-phase inclusions, mineral inclusions, etc., medium-strong polychromic. 683nm, 680nm strong absorption lines, 662nm, 646nm weak absorption lines, 630~580nm partially absorbing bands, violet zone fully absorbing |
| Aquamarine | Light green, blue-green, green-blue, light color. | None, non-luminous under X-ray irradiation | Gas-liquid two-phase inclusions, three-phase inclusions, mineral inclusions, parallel tubular inclusions, weakly to moderately polychromatic, with 537nm, 456nm weak absorption lines, 427nm strong absorption lines, the darker the color of the stone, the stronger the absorption line | |||||
| Beryl | Colorless, yellow, pink, red, blue, and black, etc. | Ei ole | Gas-liquid two-phase inclusions, various mineral inclusions, parallel tubular inclusions, etc. Polychromatic varies with the color of the gemstone; generally, the deeper the color, the stronger the polychromatic, with no weak iron absorption lines. |
| Jalokiven nimi | Väri | Kemiallinen koostumus | Taitekerroin | Suhteellinen tiheys | Kovuus | Dispersion value | UV fluorescence characterization (LW, SW) | Magnified inspection and other features |
|---|---|---|---|---|---|---|---|---|
| Dushan Jade | White, green, blue, purple, yellow, black. | Plagioclase Anorthite), Zoisite | 1.56, 1.70 | 2.90 | 6~7 | - | Ei ole | Fibrous fine-grained structure, blue, blue-green spots, green part of the red color under the Charles filter |
| Serpentine jade | Green, yellowish green, white, black, etc. | Mg6(Si4O10) (OH)8 | 1.560- 1.570 | 2.57 | 2.5-6 | - | None, occasional weak green fluorescence | Internal black mineral inclusion, white interwoven structure of strips, flakes, fibers |
| Labradorite | Orange, yellow, gray, brownish red | NaCaAlSi3O8 | 1.559- 1.568 | 2.70 | 6-6.5 | - | Ei ole | Air-liquid inclusion, dark needle-like or plate-like mineral inclusion, halo effect, solubility development |
| Scapolite | Colorless, Blue, Gray, Yellow, Maroon | Na4(AlSi3O8)3 (Cl, OH) | 1.550- 1.564 | 2.6-2.74 | 6 ~ 6.5 | - | None - strong: pink, orange, yellow | Needle, parallel tubular inclusion, solid inclusion, negative crystal, etc. A pink gemstone with 663nm and 652nm absorption lines. |
| Quartz | Colorless, purple, yellow, green, pink. | SiO2 | 1.544- 1.553 | 2.66 | 7 | - | Ei ole | Ribbons, gas-liquid inclusions, solid inclusions, negative crystals, etc., "bull's-eye" interferogram under orthogonal polarizing microscope. |
| Petrified wood | Light yellow, maroon, brownish red, black, etc. | SiO2•nH2O and C, H compound | 1.54 | 2.5-2.91 | 7 | - | Ei ole | Woody fiber-like structure, with wood grain |
| Quartzite (Aventurine) | Green, gray, yellow, brown, orange, blue | SiO2 | 1.54 | 2.64-2.71 | 7 | - | None, chromium-bearing quartzite: none-weak, grayish green or reddish | Granular structure, often containing fuchsite, with 682nm, 649nm absorption band, with alluvial effect |
| Silicified asbestos | Brownish red, brownish yellow, grayish blue, blue | Ei ole | Fibrous structure, with cat's eye effect, brownish yellow, brown-red called tiger's eye stone, gray-blue, blue called eagle's eye stone | |||||
| Chalcedony (Agate) | Various colors | SiO2 | 1.54 | 2.60 | 6.5-7 | - | None, dyed chalcedony (agate) fluoresces strongly | Cryptocrystalline structures, agate with banded and layered structures, can have a halo effect and cat's eye effect. |
| Lolite | Blue-purple, colorless, off-white, etc. | Mg2Al4Si5O18 | 1.542- 1.551 | 2.61 | 7-7.5 | - | Ei ole | Color bands, gas-liquid inclusions, hematite flake inclusions, starburst effect, cat's eye effect, etc. Strong trichromaticity, weak absorption bands at 426nm and 645nm. |
| Amber | Light yellow, yellow, fawn, red, green | C10H16O, can contains H2S | 1.537- 1.547 | 1.08 | 2-2.5 | - | LW: weak-strong blue, light yellow, light green; SW: none | Bubbles, flow-like structures, animal and plant inclusions, hot needle melting and aromatic odor, electrically charged by friction, common anomalous matting |
| Sunstone | Yellow, orange, brown, red | XAlSi3O8, X are Na and Ca | 1.537- 1.547 | 2.65 | 6 〜6.5 | - | Ei ole | Common red or gold-colored plate-like hematite inclusions with alluvial gold effect |
| Ivory | White, yellowish, light yellow, brown | Protein, collagen, elastin | 1.54 | 1.7-2.00 | 2~3 | - | LW: none; SW: weak-medium blue fluorescence | Leuze grain, wave-like structure texture, softened by nitric acid, phosphoric acid, mammoth ivory partially petrified, mainly composed of SiO2 |
| Jalokiven nimi | Väri | Kemiallinen koostumus | Taitekerroin | Suhteellinen tiheys | Kovuus | Dispersion value | UV fluorescence characterization (LW, SW) | Magnified inspection and other features |
|---|---|---|---|---|---|---|---|---|
| Shell | White, gray, yellow, etc. | CaCO3 organic matter | 1.530 〜 1.685 | 2.86 | 3~4 | - | None, stained shells fluoresce strongly | Laminar structure, surface stromatolites, blistering in hydrochloric acid |
| Amazonite | Green, Blue, Light Blue | XAlSi3O8 X are Na and K | 1.522- 1.530 | 2.56 | 6-6.5 | - | Ei ole | Common green and white lattice-like coloration, solifluction development |
| Moonstone | Colorless, Blue, Yellow | 1.518- 1.526 | 2.58 | Ei ole | "Centipede-like" inclusion, needle-like, fingerprint-like inclusion, with halo colors | |||
| Natural pearl | Colorless, Light Yellow, Light Blue, Pink, etc. | CaCO3 and C, H chemical compound | 1.530- 1.685 | 2.61-2.85 | 2.5 〜4.5 | - | Fluorescence varies from color to color, dyed pearls fluoresce more strongly | Concentric radial lamellar structure, surface growth texture, pearly luster, blistering in hydrochloric acid, pearly luster |
| Cultured pearl | Colorless, Light Yellow, Gold, Black, etc. | 2.66 ~ 2.78 | 2.5~4 | Nucleated cultured: thin pearl layer, concentric radial structure, surface texture; non-nucleated cultured: hollow in the center, pearl luster | ||||
| Lazurite | Blue, purple-blue | (Na,Ca)8(AlSiO4)6 | 1.50 | 2.25 | 5~6 | - | LW: calcite-containing fraction fluoresces pink; SW: none | Granular structure, often containing calcite, pyrite, etc., Charles color filter was Chu red, calcite content increases refractive index becomes larger |
| Natural glass | Yellow, Green, Black, Orange, Red | SiO2, can contain many impurities | 1.49 | 2.36-2.40 | 5~6 | - | Ei ole | Round or elongated bubbles, acicular crystalline inclusion, common anomalous extinction, and fracture surface can be seen as shell-like fracture |
| Marble | Various colors | CaCO3 | 1.486 〜 1.658 | 1.35, 2.65 | 3~4 | - | None, stained marble has weak to moderate fluorescence | Granular structure, laminated or striated structure, blistering in hydrochloric acid |
| Coral | Light to dark red, orange, white, black, etc. | CaCO3 | 1.486- 1.658 | 1.35, 2.65 | 3~4 | - | None, Gelatinized stones have strong fluorescence | Concentric rings in cross-section, parallel corrugated texture in longitudinal section, blistering in hydrochloric acid |
| Sodalite | Dark blue, violet blue | Na8Al6Si6O24Cl2 | 1.483 | 2.25 | 5~6 | - | Weak-medium: orange or orange-red | Granular structure, white veins, flash on the disintegrated surface, reddening under the filter lens |
| Opaali | White, orange-red, blue, green, black, etc. | SiO2 - nH2O | 1.450, can be as low as 1.37 | 2.15 | 5~6 | - | Black or white: none-medium; white, light blue, green or yellow; fire opal: none-medium; greenish brown: phosphorescent | The color spot is an irregular sheet; the color spot boundary is not obvious; the surface is silky luster and the color change effect |
| Fluorite | Colorless, Green, Blue, Yellow, Pink, Purple | CaF2 | 1.434 | 3.18 | 4 | - | Medium-strong fluorescence, varied colors, strong phosphorescence | Two-phase or three-phase inclusion, obvious color band, the development of the decohesion is triangular, part of the color change effect |
Section III Identification Characteristics of Common Synthetic Gemstones
| Jalokiven nimi | Väri | Synthesis method | Kemiallinen koostumus | Taitekerroin | Suhteellinen tiheys | Kovuus | Dispersion value | UV fluorescence characterization (LW, SW) | Magnified inspection and other features |
|---|---|---|---|---|---|---|---|---|---|
| Synthetic Moissanite | Colorless - light yellow, light blue, light green, etc. | Chemical Vapor Phase Precipitation | SiC | 2.648 ~ 2.691 | 3.22 | 9.25 | 0.104 | None - weak orange fluorescence | Punctate, filamentous inclusion with significant ghosting |
| Synthetic rutile | Colorless, light yellow, light blue, green, etc. | Flame melting method | TiO2 | 2.616 〜 2.691 | 4.26 | 6~7 | 0.330 | Ei ole | Re-imaging is obvious, clean inside, occasional bubbles, yellow and blue color |
| Synthetic diamond | Colorless, yellow, green, blue, brown, etc. | High Temperature High Pressure | C | 2.417 | 3.52 | 10 | 0.044 | LW: none; SW: weak-strong, stronger yellow and yellow-green phosphorescence | Metal inclusions such as iron and nickel, black graphite inclusions, magnetism |
| Colorless, Tawny, Blue, etc. | Chemical Vapor Phase Precipitation | LW: none; SW: none - medium, orange fluorescence | Dotted inclusions, laminated flat growth texture | ||||||
| Strontium titanate | Colorless, Green | Flame melting | SrTiO3 | 2.409 | 5.13 | 5〜6 | 0.190 | Ei ole | Internally clean, surface scratches |
| Synthetic Cubic Zirconia | Colorless, pink, red, blue, green, purple, black, etc. | Cold Crucible Shell Fusion | ZrO2 | 2.15 | 5.80- 6.00 | 8.5 | 0.060 | LW: none - medium orange; SW: none - medium yellow, yellow-green | Internally Clean, Occasional Bubbles |
| Gadolinium gallium garnet | Colorless, Light Yellow, etc. | Flame melting method | Cd5Ga5O12 | 1.970 | 7.05 | 6~7 | 0.045 | None - weak: orange fluorescence | Internal bubbles, metal inclusions, powdered raw material inclusions, adamantine luster |
| Yttrium aluminum | Colorless, Green, Blue, etc. | Crystal lifting method | Y3AI5O12 | 1.833 | 4.50- 4.60 | 8 | 0.028 | None - weak: orange fluorescence, yellow with strong yellow fluorescence | Internally Clean, Occasional Elongated Bubbles Visible |
| Synthetic ruby | Medium-Dark Red | Flame melting | Al2O3 | 1.762 〜 1.770 | 4.0 | 9 | 0.018 | Medium-strong: red fluorescence | Curved Growth Patterns, White Powdered Inclusion |
| Hydrothermal method | Medium-strong: red fluorescence | Fingerprint Inclusion, Flat Growth Texture | |||||||
| Flux method | Medium-strong: red fluorescence | Flux Residue, Metal Clad | |||||||
| Crystal lifting | None - Medium: red fluorescence | Internally Clean, Occasional Elongated Bubbles | |||||||
| Synthetic Sapphire | Colorless, Blue, Yellow, Green, Pink, etc. | Flame-melting | Al2O3 | 1.762- 1.770 | 4.0 | 9 | 0.018 | Fluorescence characteristics change with different colors | Curved Growth Texture, White Powdered Clad Body |
| Hydrothermal | Fingerprint Inclusion, Flat Growth Texture | ||||||||
| Flux method | Flux Residue, Metal Clad | ||||||||
| Crystal lifting | Internally Clean, Occasional Elongated Bubbles |
| Jalokiven nimi | Väri | Synthesis method | Kemiallinen koostumus | Taitekerroin | Suhteellinen tiheys | Kovuus | Dispersion value | UV fluorescence characterization (LW, SW) | Magnified inspection and other features |
|---|---|---|---|---|---|---|---|---|---|
| Synthesized Starlight Red and Sapphire | Red, light yellow, light blue, green, etc. | Flame melting | AI2O3•TiO2 | 1.762- 1.770 | 4.0 | 9 | 0.018 | Synthetic Star Ruby: medium-strong red; Synthetic Star Sapphire: LW, none; SW, weak blue-white | Uniform thickness of star lines, clear intersections of star lines, starlight floating on the surface, curved growth lines visible inside, white powdery inclusions |
| Synthetic Emeralds | Green color | Hydrothermal method | BeAlSi2O6 | 1.560- 1.578 | 2.65 ~ 2.73 | 7.5 | 0.014 | Medium-strong: red | Seed crystals, water ripple texture, nail-like inclusions; only type I water in the structure tested by infrared spectroscopy |
| Flux method | Medium-strong: red | Flux Residue, Metal Clad | |||||||
| Synthetic Alexandrite | Daylight: green; incandescent: red | Crystal lifting | BeAl2O4 | 1.740 〜 1.749 | 3.73 | 8.5 | 0.018 | Medium-strong: red | Internally clean, occasional elongated bubbles visible, curved growth lines |
| Synthetic Spinel | Blue, red, purple, pink, colorless, etc. | Flame melting | MgAl2O4 | 1.728 | 3.64 | 8 | 0.020 | Chromium-bearing: none - medium red fluorescent Cobalt: LW red, SW blue-white | Internally clean, occasional bubbles visible, reddening under Charles filter, unusual matting |
| Synthetic Turquoise | Green, blue, etc. | Chemical precipitation | CUAl6(PO4)4 (VOI)8•5H2O | 1.60- 1.65 | 2.6 ~ 2.9 | 5~6 | - | Ei ole | Fine-grained structure, black to dark brown reticulated iron lines |
| Synthetic Aquamarine | Light blue, blue, etc. | Hydrothermal | BeAlSi2O6 | 1.575- 1.583 | 3.64 | 7.5 | 0.014 | Ei ole | Clear boundaries around seed crystals, crystalline inclusion, only type I water in infrared spectroscopic tests |
| Synthetic Lapis Lazuli | Blue, indigo | Chemical precipitation | Differences in composition from natural lapis lazuli | 1.55 | 2.33- 2.53 | 4.5 | - | Ei ole | Uniform distribution of pyrite, flat corners, uniform size |
| Synthetic Crystal | Colorless, purple, green, blue, yellow, etc. | Hydrothermal | SiO2 | 1.544- 1.553 | 2.65 | 7 | 0.012 | Ei ole | Seed crystals, “table dust” inclusion, flat color bands, warm to touch |
| Synthetic Opal | White, black, blue, etc. | Chemical precipitation | SiO2•nH2O | 1.42-1.46 | 1.97- 2.20 | 5.5~ 6.5 | - | Ei ole | Clearly delineated color spots, mosaic structure, columnar color spots, lizard skin-like structure |
| Plastic | Various colors | Muut | Variable composition | 1.46-1.47 | 1.05- 1.55 | 1.5-3 | - | Variable, often chalky | Internal flow patterns, bubbles, mold features, often with scratches and pits on the surface |
| Glass | Various colors | Muut | SiO2 | 1.48-1.70 | 2.30 〜 4.50 | 5〜6 | - | Variable, often chalky | Internal flow pattern, air bubbles, shell-like structure on the fracture surface, with mold features. |
