Gemstone Identification Chart

Note: We have Tried our best to provide gemstone identification chart Which is available around website and collected from many sources from authentic books which referenced by GIA. To made Gemstone identification Easy. You Can use below search bar to find the specific gemstone by typing it’s gemstone name example “corundum”. You can also use the arrow mark to sort in various orders.
Refractive Index is the most important testing factor, so the values given for these are published in ascending order. The specific gravity values, rather less used in gem testing, in most cases increase with increasing refractive index and fall within limits into defined groups, and therefore may be readily found in the table. Where constants are outside the given range, or may not easily be found within that range; The word ‘to’ between figures implies variation in range, while ‘–’ indicates the greatest and least readings in doubly refractive stones. ‘I’ means isotropic, ‘U’ uniaxial, and ‘B’ Biaxial. Glass imitation stones commonly have refractive Index which lie between 1.50 and 1.70.[/vc_column_text][vc_empty_space][vc_column_text]

Name	Refractive index	Birefringence	Optic sign	Optical character	Hardness	Specific gravity	Luster	Colors
Sellaite	1.378–1.390	0.012	Positive	U	5 to 6	3.15	Vitreous	Colorless to white
Fluorite	1.434	—	—	I	4	3.18	Vitreous	All Colors
Fire opal	1.435 to 1.455	—	—	—	—	1.97 to 2.06	Subvitreous to waxy	Colorless, white, yellow, red, orange, green, brown, black, blue, pink
Opal	1.44 to 1.46	—	—	I	5.5 to 6	1.98 to 2.20	Subvitreous to waxy	Colorless, white, yellow, red, orange, green, brown, black, blue, pink
Silica glass	1.46	—	—	I	6	2.21	—	—
Creedite	1.460–1.485	0.025	—	B	3.5	2.71	Vitreous	Colorless, white, violet, orange
Thaumasite	1.464– 1.500 to 1.468–1.507	0.031 to 0.043	Negative	U	3.5	1.88 to 1.90	Vitreous to silky	Colorless, white, pale yellow
Sodalite	1.48	—	—	I	5.5 to 6	2.15 to 2.35, usually 2.25 to 2.3	Dull vitreous to greasy	Rich royal blue, green, yellow, violet, white veining common
Natrolite	1.480–1.493	0.013	Positive	B	5.5	2.20 to 2.25	Vitreous, Silky, Pearly	White, colorless, sometimes pink
Obsidian	1.48 to 1.51	—	—	I	5	2.33 to 2.42	Vitreous	Deep black or blackish green
Moldavite	1.48 to 1.54	—	—	I	5.5	2.34 to 2.39	Vitreous	Mossy green
Calcite	1.486 –1.658	0.172	Negative	U	3	2.71	Vitreous to pearly on cleavage surfaces	Colorless or white, also gray, yellow, green,
Calcite(marble)	1.486– 1.658	—	—	—	3	2.71	Vitreous to pearly on cleavage surfaces	Colorless or white, also gray, yellow, green,
Coral	1.486 to 1.658	0.172	—	—	3.5	2.6 to 2.7	Opaque	White, Pink, Red, Black
Analcime	1.487	—	—	I	5 to 5.5	2.20 to 2.29	Vitreous	White, colorless, gray, pink, greenish, yellowish
Whewellite	1.490 –1.650	0.16	Positive	B	2.5	2.23	Vitreous, Pearly	White, yellow, brown,
Tektites	1.49 to 1.53	—	—	I	5	2.36 to 2.51	—	—
Yugawaralite	1.492 –1.504	0.009	Positive	B	4.5	2.19 to 2.22	Vitreous, Pearly	Colourless, white
Celluloid	1.495 –1.510	—	—	I	1.5	1.36 to 1.42	—	—
Cellulose Acetate	1.495–1.505	—	—	—	1.5	1.29 to 1.40	—	—
Celluloid	1.495 to 1.510	—	—	I	1.5	usually 1.36 to 1.80, 1.36 to 1.42	—	—
Haüyne	1.496	—	—	I	5.5 to 6.5	2.4	Vitreous to greasy	Blue, white, gray, yellow, green, pink
Tugtupite	1.496–1.502	0.006	Positive	U	6	2.36 to 2.57	Sub-Vitreous, Waxy, Greasy, Dull	Commonly red, also white to pink, bluish white, greenish white
Perspex	1.5	—	—	I	2	1.18 to 1.19	—	—
Lapis lazuli	1.5	—	—	I	5.5	2.70 to 2.90	dull	Blue, mottled with white calcite and brassy pyrite
Mesolite	1.50 (mean)	0.001	Positive	B	5	2.29	Vitreous, silky when fibrous	Colorless, white, gray, yellowish brown
Dolomite	1.502– 1.681	0.179	Negative	U	3.5 to 4	2.8 to 2.9	Vitreous to pearly	White, gray to pink
Petalite	1.504–1.516	0.012	Positive	B	6 to 6.5	2.39 to 2.46	Vitreous, pearly on cleavages	Colorless, grey, yellow, pink, to white
Ulexite	1.51 (mean)	0.02	Positive	B	1	1.65 to 2.00	Vitreous; silky or satiny in fibrous aggregates	Colorless to white
Leucite	1.51 (mean)	0.001	Positive	U	5.5 to 6	2.45 to 2.50	Vitreous	White to grey
Cancrinite	1.51 (mean)	0.022	Negative	U	6	2.42 to 2.50	Vitreous, greasy, pearly	Grey-green, white, yellow, blue, orange, reddish
Poudretteite	1.511 to 1.532	0.021	Positive	U	5	2.51	Vitreous (Glassy)	Colorless, Light pink
Scolecite	1.512–1.523	0.011	Negative	B	5 to 5.5	2.21	Vitreous, silky when fibrous	Colorless white, pink, salmon, red or green
Magnesite	1.515– 1.717	0.202	Negative	U	3.5 to 4.5	3.00 to 3.12	Vitreous	Colorless, white, pale yellow, pale brown, faintly pink, lilac-rose
Pollucite	1.517 to 1.525	—	—	I	6.5	2.85 to 2.94	Vitreous to greasy	Usually colorless, also white, grey, pink, blue or violet
Sanidine	1.518–1.524	0.006	Negative	B	—	2.57 to 2.58	Vitreous, pearly on cleavage	Colorless to white
Thomsonite	1.52–1.54	0.028	Positive	B	5 to 5.5	2.3 to 2.4	vitreous, pearly	colorless, white, beige,and pink
Orthoclase feldspar (moonstone)	1.52–1.53 to 1.53–1.54	0.008	Negative	B	6	2.56 to 2.59	Vitreous, pearly on cleavage surfaces	Colorless, greenish, greyish yellow, white, pink
Stichtite	1.52–1.55	0.027	Negative	U	2.5	2.15 to 2.22	Waxy to resinous	Lilac to rose-pink
Gypsum (alabaster)	1.52–1.53	0.01	Positive	B	1.5 to 2	2.30 to 2.33	Vitreous to silky, pearly, or waxy	Colorless to white; may be yellow, tan, blue, pink, brown, reddish brown or gray due to impurities
Microcline feldspar	1.522–1.530	0.008	Negative	B	6.5	2.56 to 2.58	Vitreous	Colorless
Yellow orthoclase feldspar	1.522–1.527	0.005	Negative	B	6	2.56	Vitreous	Green, Yellow
Milarite	1.529–1.532 to 1.548–1.551	0.003	Negative	U	5.5 to 6	2.46 to 2.61	—	—
Lepidolite	1.530–1.556	0.026	Negative	B	3.5 to 4	2.8 to 3.3 , usually 2.80 to 2.9	Vitreous to pearly	Pink, purple, rose-red, violet-gray, yellowish, white, colorless
Iolite	1.53–1.54 to 1.54–1.55	0.008 to 0.012	Negative	B	7	2.57 to 2.66,usually 2.57 to 2.61	Greasy or vitreous	Blue, smoky blue, bluish violet; greenish, yellowish brown, gray; colorless to very pale blue in thin section
Aragonite	1.530– 1.685	0.155	Negative	B	3.5 to 4	2.93 to 2.95	Vitreous, resinous on fracture surfaces	White, red, yellow, orange, green, purple, grey, blue and brown
Amazonite	1.52 to 1.53	0.008	Negative	—	6 to 6.5	2.56 to 2.58	Vitreous	Blue, Green, Purple, Gray, Multicolored
Meerschaum	1.53 (mean)	—	—	—	2	1.00 to 2.00	—	—
Chalcedony	1.530 to 1.539	0.004 (av.)	Negative	B	7	2.58 to 2.62	Waxy, vitreous, dull, greasy, silky	Various
Pearl	1.530 to 1.685	1.55	—	—	3.5 to 4	2.20 to 2.78	—	white, pink, silver, cream, brown, green, blue, black, yellow, and purple
Witherite	1.532–1.680	0.148	Negative	B	3.5	4.27 to 4.35	Vitreous, resinous on fractures	Colorless, white, pale gray, with possible tints of pale-yellow, pale-brown, or pale-green
Apophyllite	1.535–1.537	0.002	Pos/Neg	U	4.5 to 5	2.30 to 2.50	Vitreous; pearly	Usually white, colorless; also blue, green, brown, yellow, pink, violet
Bone	1.54	—	—	—	2.5	2	—	—
Copal resin	1.54	—	—	I	2	1.03 to 1.10	—	—
Vegetable ivory	1.54	—	—	—	2.5	1.38 to 1.42	—	—
Dentine ivory	1.54	—	—	—	2.25 to 2.5	1.70 to 1.98	—	—
Amber	1.54	—	—	I	2 to 2.5	1.03 to 1.10
Nepheline	1.54	0.004	Negative	U	5.5 to 6	2.55 to 2.65	Vitreous - greasy	White, Gray, Brown, Brownish gray, Reddish white
Albite feldspar	1.54 approx.	0.011	Positive	B	6 to 6.5	2.62	Vitreous, typically pearly on cleavages	White to gray, blueish, greenish, reddish; may be chatoyant
Soapstone	1.54 approx.	—	—	B	1 to 2	2.7 to 2.8	—	—
Jasper	1.54 approx.	—	—	—	7	2.58 to 2.91	Vitreous	White, Blue, Red, Green, Yellow, Orange, Brown, Gray, Black, Banded, Multicolored
Oligoclase feldspar (sunstone)	1.542–1.549	0.007	Negative	B	6 to 6.5	2.62 to 2.65	Vitreous. Pearly on cleavage surfaces.	Colorless, yellow, red, green, blue, and copper shiller
Quartz	1.544–1.553	0.009	Positive	U	7	2.65	Vitreous – waxy to dull when massive	Colorless through various colors to black
Scapolite (pink	1.544–1.560	0.016	Negative	U	6	2.63	Vitreous	White, Colorless, Yellow, Orange, Brown, Pink, Purple
Scapolite (yellow)	1.548–1.568	0.02	Negative	U	6	2.71	Vitreous	White, Colorless, Yellow, Orange, Brown, Pink, Purple
Tortoise-shell and horn	1.55	—	—	—	2.5	1.26 to 1.35	—	—
Charoite	1.550–1.559	0.009	Positive	B	5 to 6	2.54 to 2.68	Vitreous to pearly	Violet, lilac, light brown
Pyrophyllite	1.55– 1.60	—	—	—	1.5	2.8	Pearly to dull	Brown green, brownish yellow, greenish, gray green, gray white
Saussurite	1.55–1.70	—	—	—	6.5	2.7 to 3.4	—	—
Casein (protein plastic)	1.55 to 1.56	—	—	I	2.5	1.32 to 1.34	—	—
Casein plastic	1.55 to 1.56	—	—	I	2.25	1.32 to 1.34	—	—
Hambergite	1.553 –1.625 to 1.559–1.631	0.072	Positive	B	7.5	2.35	Vitreous	Colorless, pale gray, pale yellow
Beryllonite	1.553–1.562	0.009	Negative	B	5.5 to 6	2.80 to 2.85	Vitreous to adamantine, may be pearly on {010}	Colorless, white to pale yellow
Synthetic emerald (flux melt)	1.558–1.563	0.003	Negative	U	7.5	2.65	Opaque	Black
Black coral	1.56	—	—	—	3.5	1.34	—	—
Deer horn	1.56	—	—	—	2.5	1.60 to 1.85	—	—
Serpentine (bowenite)	1.56	—	Negative	B	2.5 to 4	2.5 to 2.7, 2.58 to 2.62	Greasy, waxy, or silky	White, yellow, green, gray, brown, black, purple; sometimes multicolored, especially green and yellow.
Labradorite feldspar (yellow)	1.560–1.568 to 1.565–1.573	0.008	Positive	B	6 to 6.5	2.68 to 2.69	Vitreous to pearly on cleavages	Gray, brown, greenish, blue, yellow, colorless
Emerald	1.56–1.57 to 1.59–1.60	0.006 to 0.007	Negative	U	7.5	2.69 to 2.75	Vitreous	Green shades to colorless
Variscite	1.56 (mean)	—	Negative	B	5	2.4 to 2.6	Vitreous to waxy	Green, blue green, yellow green and rarely red
Brazil (some)	1.566–1.571	0.005	—	—	—	2.69	—	—
Bytownite feldspar	1.567–1.576	0.009	Negative	B	6 to 6.5	2.73	Vitreous, pearly on cleavages	Colorless, white, gray
Chrysocolla	1.575 - 1.585	0.023 - 0.050	Negative	B	2.5 - 3.5	1.9 - 2.4	Vitreous to dull	Blue, cyan or blue-green, green
Pseudophite	1.57	0.003	Pos/Neg	B	2.5	2.60 to 2.85	—	—
Serpentine (williamsite)	1.57	—	Negative	B	2.5	2.61	Greasy, waxy, or silky	White, yellow, green, gray, brown, black, purple; sometimes multicolored, especially green and yellow.
Aquamarine	1.570–1.575 to	0.005 to 0.006	Negative	U	7.5	2.68 to 2.73	Vitreous	Blue
Odontolite	1.57– 1.63	—	—	Vitreous	5	3.00 to 3.10	—	—
Ophicalcite(Connemara marble)	1.57 approx.	—	—	—	3 to 4	2.7 approx.	—	—
Bastite	1.57 to 1.58	—	Negative	B	3.5 to 4	2.5 to 2.7	—	—
Colombia (Chivor)	1.571–1.577	0.006	—	—	—	2.69	—	—
Anhydrite	1.571 –1.614	0.043	Positive	B	3 to 3.5	2.90 to 2.98	Pearly on {010} vitreous to greasy on {001} vitreous on {100}	Colorless to pale blue or violet if transparent; white, mauve, rose, pale brown or gray from included impurities
Augelite	1.574–1.588	0.014	Positive	B	5	2.7	Vitreous, pearly on {110} cleavage	Colorless to white, may be yellowish to pale rose, greenish
Colombia (Muzo)	1.578–1.584	0.006	—	—	—	2.71	—	—
Tanzania	1.578–1.585	0.007	—	—	—	2.74	Vitreous, pearly on cleavage surfaces	Blue, Violet
yellow and some pink beryls	1.580–1.586	—	—	—	—	2.68 to 2.73	Vitreous to resinous	Green, blue, yellow, colorless, pink and others
Some white and pink beryls	1.58–1.59 to1.59–1.60	0.008 to 0.009	Negative	U	7.5	2.80 to 2.90	Vitreous to resinous	Green, blue, yellow, colorless, pink and others
Vivianite	1.580– 1.627	0.047	Positive	B	2	2.6	Vitreous, pearly on the cleavage, dull when earthy	Colorless, very pale green, becoming dark blue, dark greenish blue, indigo-blue, then black with oxidation
Verdite	1.58 (mean)	—	—	—	3	2.80 to 2.99	Vitreous, silky, pearly	Green
Russia and Brazil	1.581–1.588	0.007	—	—	—	2.74	—	—
Catapleiite	1.582– 1.627	0.028	Positive	U	6	2.73 to 2.90	Vitreous, Dull	Dark brown, reddish brown, flesh red, yellowish red,colourless, light grey, beige to tan, light yellow, orange, light blue
Xonotlite	1.583–1.593	0.01	Positive	B	5 to 6	2.7	Vitreous - Silky	Colorless, Gray, Lemon white, Light gray, Pink.
Zambia	1.583–1.590	0.007	—	—	—	2.74	—	—
Habachtal	1.584–1.591	0.007	—	—	—	2.74	—	—
India	1.585–1.595	0.007 to 0.010	—	—	—	2.73 to 2.74	—	—
Zimbabwe	1.586–1.593	0.007	—	—	—	2.75	—	—
Transvaal	1.586–1.593	0.007	—	—	—	2.75	—	—
Colemanite	1.586 –1.614	0.028	Positive	B	4.5	2.42	Vitreous	Colorless, white, yellowish, grey
Pakistan	1.588–1.595	0.006	—	—	—	2.76	—	—
Polystyrene	1.59	—	—	I	2.25	1.05	—	—
Larimar	1.59 to 1.65	0.038	—	—	4.5 to 6	2.70 to 2.90	Silky	White, blue, green-blue, multicolored
Howlite	1.59 (mean)	0.02	Negative	B	3.25	2.58	Subvitreous, glimmering	Colorless, Gray, White
Melinophane	1.593– 1.612	0.019	Negative	U	3.5	3	Vitreous	Colorless, shades of yellow. reddish.
Phosphophyllite	1.595– 1.616	0.021	Positive	B	3.5	3.1	vitreous	blue-green to colourless
Pectolite	1.595 –1.633	0.038	Positive	B	5 to 6	2.62 to 2.88	Silky, vitreous	Colorless, whitish, grayish, yellowish
Wardite	1.595 (mean)	0.009	Positive	U	5	2.81	Vitreous	White, colorless, pale green, blue-green, yellow-green, pale yellow, yellow pink.
Ekanite	1.597	—	—	I	6 to 6.5	3.28	Vitreous	Green, yellow, dark red
Eudialyte	1.598– 1.602 to 1.610–1.611	0.004	Positive	U	5 to 6	2.8 to 3.1	Vitreous	Red, magenta, brown; also blue and yellow
Termolite	1.599 to 1.637	0.026	Negative	B	5 to 6	2.99 to 3.03	Vitreous and silky	White, gray, lavender to pink, light green, light yellow
Nephrite	1.60–1.63 to 1.62–1.65, mean 1.62	0.027	Negative	B	6.5	2.90 to 3.02	dull	Translucent to opaque and often mottled. Light to dark green, yellow to brown, white, gray, black.
Rhodochrosite	1.60 –1.82	0.22	Negative	U	4	3.50 to 3.65	Vitreous to pearly	Pink, rose-red, cherry-red, yellow, yellowish gray, cinnamon-brown, may be banded
Chondrodite	1.60 (mean)	—	Positive	B	6.5	3.1 to 3.2	Vitreous to Greasy	Yellow, orange, red or brown, rarely colorless
Vulcanite	1.60 to 1.63	—	—	I	2	1.15 to 1.20	Metallic	Pale to yellow bronze
Vulcanite (hard rubber)	1.60 to 1.63	—	—	—	2	1.15 to 1.20	—	—
Grandidierite	1.602–1.639	0.037	Negative	B	7.5	3	Vitreous, Pearly	Bluish green
Brazilianite	1.603–1.623	0.02	Positive	B	5.5	2.980 to 2.995	Vitreous	Yellow, green, colorless
Sogdianite	1.606–1.608	0.002	Negative	U	6 to 7	2.76 to 2.90	Vitreous	Violet, pale pink
Sugilite	1.607–1.610	0.004	Negative	U	5.5 to 6.5	2.74	Vitreous	Light brownish-yellow, purple, violet, reddish violet, pale pink, colorless
Topaz	1.610–1.638	0.008 to 0.010	Positive	B	8	3.53 to 3.56	Vitreous	Colorless (if no impurities), blue, brown, orange, gray, yellow, green, pink and reddish pink
Prehnite	1.61–1.64	0.03	Positive	B	6	2.8 to 2.95, usually 2.88 to 2.94	Vitreous to pearly	Yellow-green, brown-yellow, gray, white and colorless
Persian and Egyptian Turquoise	1.61–1.65	0.04	Positive	B	5.5 to 6	approx. 2.8	Waxy to subvitreous	Turquoise, Blue, blue-green, green
American Turquoise	1.61–1.65	0.04	Positive	B	5.5 to 6	approx. 2.6	Waxy to subvitreous	Turquoise, Blue, blue-green, green
Turquoise	1.61–1.65	0.04	Positive	B	5.5 to 6	2.6 to 2.85	Waxy to subvitreous	Turquoise, Blue, blue-green, green
Herderite	1.61 (mean)	0.03	Positive	B	5	3	Vitreous	Colourless, pale yellow, greenish-white
Sugilite	1.610 to 1.607	0.003	Negative	U	6 to 6.5	2.74	Vitreous	Light brownish-yellow, purple, violet, reddish violet, pale pink, colorless
Bakelite	1.61 to 1.66	—	—	—	2.25	1.25 to 2.00 , usually 1.26 to 1.30	—	—
Gaspeite	1.61 to 1.81	0.22	—	—	4.5 to 5	3.7	Vitreous to dull	Pale green, apple-green, yellowish-green, bright green
Bakelite (higher if filled)	1.61 to 1.66	—	—	—	2.5	1.25 to 1.30	—	—
Amblygonite	1.611–1.637	0.026	Positive	B	6	3.01 to 3.03	Vitreous to pearly[	Generally white or creamy, but can also be colorless or pale yellow, green, blue, beige, gray, brown or pink.
Hemimorphite	1.612–1.633	0.021	Positive	B	5	3.44	Vitreous, adamantine, rarely silky	White, blue, greenish
Lazulite	1.615–1.645	0.036	Negative	B	5.5	3.1	Vitreous	Azure-blue, sky-blue, bluish white, yellow-green, blue-green, rarely green
Wollastonite	1.616–1.631	0.015	Negative	B	4.5 to 5	2.8 to 2.9	Vitreous or dull to pearly on cleavage surfaces	White, colorless or gray
Tourmaline	1.616–1.634 to 1.630–1.652	0.014 to 0.022	Negative	U	7 to 7.5	3.00 to 3.12	Vitreous, sometimes resinous	Most commonly black, but can range from colorless, brown, violet, yellow, orange, blue, red, green, pink, or bi-colored, or even tri-colored.
Actinolite	1.620–1.642	0.022	Negative	B	5 to 5.5	3.05	vitreous to dull	pale to dark green, yellowish green and black. White or grey when in asbestos
Smithsonite	1.62– 1.85	0.23	Negative	U	5	4.30 to 4.35	Vitreous, may be pearly	White, grey, yellow, green to apple-green, blue, pink, purple, bluish grey, and brown
Clinohumite	1.623–1.651 to 1.632–1.662	0.024 to 0.037	Positive	B	6 to 6.5	3.18	Vitreous to resinous	Brownish to orange, yellow, red
Celestine	1.625–1.635	0.01	Positive	B	3.5	3.97 to 3.99	Vitreous, pearly on cleavages	Colorless, white, pale blue, pink, pale green, pale brown, black
Datolite	1.625–1.669	0.044	Negative	B	5	2.9 to 3.00	Vitreous, rarely subresinous on fracture surface	Colorless or white; may be grayish, yellow, green, red, pink
Friedelite	1.629–1.664	0.035	Negative	U	4 to 5	3.06 to 3.19	Vitreous (Glassy)	an, brown, "beef steak"
Danburite	1.630–1.636	0.006	Negative	B	7	3	Vitreous – greasy	Colourless, white, gray, brownish white, straw yellow
Apatite	1.63–1.64	0.002 to 0.004	Negative	U	5	3.17 to 3.23	Vitreous to subresinous	Transparent to translucent, usually green, less often colorless, yellow, blue to violet, pink, brown.
Siderite	1.633 –1.873	0.24	Negative	U	3.5 to 4	3.83 to 3.88	Vitreous, may be silky to pearly	Pale yellow to tannish, grey, brown, green, red, black and sometimes nearly colorless
Andalusite	1.634–1.644 to 1.641–1.648	0.007 to 0.011	Negative	B	7.25	3.15 to 3.17	Vitreous	Pink, violet, yellow, green, white, gray; in thin section, colorless to pink or green
Barite / Baryte	1.636–1.648	0.012	Positive	B	3	4.3 to 4.6	Vitreous, Pearly	Colorless, white, light shades of blue, yellow, grey, brown
Jeremejevite	1.639–1.648	0.009	Negative	U	6.5 to 7	3.29–3.31	Vitreous	Colorless, white, yellowish, blue
Väyrynenite	1.639–1.667	0.026	Negative	B	5	3.23	Vitreous	Light pink to rose-red, salmon pink, pale gray, brown
Eosphorite	1.640–1.645 to 1.668–1.680	0.028 to 0.035	Negative	B	4.5	3.1	Vitreous, resinous	usually pale brown, golden brown, also medium brown to dark brown; occasionally pink, rose red
Jet	1.64 to 1.68	—	—	—	2.5 to 4	usually 1.20 to 1.30	Velvety to waxy	Deep black, dark brown
Ludlamite	1.650–1.689 to 1.653–1.693	0.04	Positive	B	3 to 4	3.19	Vitreous, pearly on cleavage	Apple-green to bright green
Malachite	1.65– 1.90	0.25	Negative	B	4	3.74 to 3.95, usually 3.8	Adamantine to vitreous; silky if fibrous; dull to earthy if massive	Bright green, dark green, blackish green, commonly banded in masses; green to yellowish green in transmitted light
Euclase	1.652–1.672	0.02	Positive	B	7.5	3.1	Vitreous	Colorless, white, pale green to deep yellowish green, greenish blue, pale blue to deep blue
Peridot	1.654–1.689	0.036	Positive	B	6.5	3.34	Vitreous (glassy)	Yellow, to yellow-green, olive-green, to brownish, sometimes a lime-green, to emerald-ish hue
Phenakite	1.654–1.670	0.016	Positive	U	7.5 to 8	2.95 to 2.97	Vitreous	Colorless, yellow, pink, brown
Jadeite	1.654–1.667, mean 1.66	0.013	Positive	B	7	3.30 to 3.36	Subvitreous, pearly on cleavages	Apple-green, emerald-green, bluish green, leek-green,greenish white, white, may show green spots, rarely blue or violet; colorless in thin section. Often also banded.
Magnesioaxinite	1.656–1.668	0.012	Negative	B	6.5 to 7	3.18	Vitreous	Pale Blue to pale Violet; light Brown to light Pink `
Fibrolite	1.658–1.678	0.02	Positive	B	6.5 to 7	3.25	Vitreous	Blue, brown, colourless, green, grey
Sillimanite	1.659 - 1.680	0.015 to 0.011	—	—	6 to 7.5	3.25 +/-, 0.02, 0.11	Vitreous to subadamantine, silky	Colourless or white to grey, also brown, yellow, yellow-green, grey-green, blue-green, blue; colourless in thin section
Spodumene	1.660–1.675	0.015	Positive	B	7	3.17 to 3.19	Vitreous, pearly on cleavage	Highly variable: white, colorless, gray, pink, lilac, violet, yellow and green, may be bicolored; emerald green - hiddenite; lilac - kunzite; yellow - triphane
Serandite	1.660–1.688	0.028	Positive	B	4.5 to 5	3.32	Vitreous, greasy	Pink, orange, red, tan, and brown. May oxidize brown or black upon exposure to air.
Boracite	1.66 to 1.67	—	—	I	7	2.96	Vitreous - adamantine	Colorless, white, gray, brown, orange, yellow, pale green, dark green, blue-green, or blue; colorless in transmitted light
Durangite	1.662 –1.712	0.05	Negative	B	5	3.97 to 4.07	Vitreous	Light to dark
Enstatite	1.663–1.673	0.01	Positive	B	5.5	3.26 to 3.28	Vitreous, pearly on cleavage	White, grey, green, yellow or brown - colorless in thin section.
Kornerupine	1.665–1.678 to 1.668–1.680	0.013	Negative	B	6.5	3.28 to 3.35	Vitreous	Colorless, white, grey, greenish, bluish, brown, black
Lawsonite	1.665–1.684	0.019	Positive	B	7 to 8	3.09	Vitreous, greasy	Colorless, white, pale blue to grayish blue
Hypersthene	1.67–1.68 to 1.71–1.73	0.010 to 0.020	Negative	B	5 to 6	3.4 to 3.5	vitreous to pearly	gray, brown, or green
Diopside	1.67 –1.70	0.03	Positive	B	5.5	3.29	Vitreous to dull	Commonly light to dark green; may be blue, brown, colorless, white, grey
Sinhalite	1.67 –1.71	0.038	Negative	B	6.5	3.47 to 3.49	Vitreous	Colourless, yellow-brown, green-brown, brown
Parisite	1.671– 1.772	0.01	Positive	U	4.5	4.33	Vitreous - greasy	Brown, brownish yellow, gray-yellow, grayish yellow, yellow, waxy yellow, colourless to yellow in transmitted light
Legrandite	1.675 –1.735	0.06	Positive	B	5	3.98 –4.04	Vitreous	Bright yellow, wax-yellow, colorless
Axinite	1.675–1.685	0.01	Negative	B	7	3.27 to 3.29	Vitreous	Reddish brown to yellow to colorless. Blue, violet, grey.
Dumortierite (massive)	1.68 (mean)	—	—	B	7	3.26 to 3.41	Vitreous to dull	Blue, greenish-blue, violet-blue, pale blue, red
Triphylite	1.689–1.695 to 1.694–1.702	0.006 to 0.008	Positive	B	4 to 5	3.42 to 3.52	Vitreous–subresinous	Green–blue gray, brown–black
Rhodizite	1.69	—	—	I	8	3.4	Adamantine, Vitreous	Colourless, white, greyish, yellowish; colourless in transmitted light
Willemite	1.69– 1.72	0.028	Positive	U	5.5	3.89 to 4.18	Vitreous to resinous	Colorless to white, gray, flesh-red, dark brown, honey-yellow, apple-green, blue
Zoisite	1.692– 1.700	0.008	Positive	B	6	3.35	Vitreous, pearly on cleavage surfaces	White, gray, greenish brown, greenish gray, pink, blue, purple
Idocrase	1.700–1.712	0.005 (mean)	Neg/Pos	U	6.5	3.32 to 3.47	Vitreous to resinous	Yellow, green, brown; colorless to white, blue, violet, bluish green, pink, red, black, commonly zoned
Thulite (zoisite)	1.700–1.706	0.006	Negative	B	6	3.09 to 3.12	Vitreous, pearly on cleavage surfaces	Pink
Serendibite	1.700–1.743	0.006	Positive	B	6.5 to 7	3.42 to 3.52	Vitreous	pale yellow, blue-green, greyish blue, black
Chlorastrolite	1.70 (mean)	—	—	B	5 to 6	3.1 to 3.5	—	—
Smaragdite	1.70 approx.	—	—	—	5 to 5.5	3.25	Vitreous	Emerald green
Diaspore	1.702–1.750	0.048	Positive	B	6.5 to 7	3.30 to 3.35	Adamantine, vitreous, pearly on cleavage faces	White, pale gray, colorless, greenish gray, brown, pale yellow, pink, purple; may exhibit color change
Arandisite	1.704 approx.	—	—	—	5	4	—	Bright green
Sapphirine	1.705–1.711	0.006	Neg/Pos	B	7.5	3.40 to 3.58	Vitreous	Light to dark blue or green, white, gray, pale red, yellow
Adamite	1.710–1.759 to 1.742–1.773	0.031 to 0.050	Positive	B	3.5	4.30 to 4.68	Vitreous	Pale yellow, honey-yellow, brownish yellow, reddish; rarely white, colorless, blue, pale green to green, may be zoned;
Spinel	1.714 to 1.736	—	—	I	8	3.58 to 3.64	Vitreous	Various; red, pink, blue, lavender/violet, dark green, brown, black, clear
Kyanite directional	1.715–1.732	0.017	Negative	B	5 to 7	3.65 to 3.68	Vitreous to pearly	Blue, white, rarely green, gray, yellow, pink, orange, and black, can be zoned
Taaffeite	1.718–1.722	0.004	Negative	U	8	3.60 to 3.61	Vitreous	Colorless, greyish violet, violet red, red, greenish, light green, pink violet, mauve
Massive grossular garnet	1.72	—	—	I	7.25	3.36 to 3.55	greasy to vitreous	light to dark green, light to dark yellow to reddish brown, occasionally translucent to opaque pink. It is also but rarely found in colorless form[1]
Hydrogrossular	1.72	—	—	—	7	3.47 to 0.08 - 0.32	vitreous	green to bluish green, pink, white, gray
Clinozoisite	1.72–1.73	0.01	Positive	B	6 to 6.5	3.37	Vitreous	Colorless, green, gray, light green, yellow green
Bromellite	1.720–1.735	0.015	Positive	U	9	3.00 to 3.02	Vitreous	White, colorless
Hodgkinsonite	1.720–1.746	0.026	Negative	B	4.5 to 5	3.95	Vitreous (Glassy)	Light pink, Orange, Reddish brown.
Synthetic spinel	1.724 to 1.729	—	—	I	8	3.61 to 3.65	Subadamantine To Vitreous	red, yellow, brown, light to dark green, grayish green, yellowish green, pale pink to pink, light to dark blue, greenish blue, violet, mauve, orange, colorless
Azurite	1.73 –1.84	0.11	Positive	B	3.5 to 4	3.77 to 3.89	Vitreous	Azure-blue, Berlin blue, very dark to pale blue; pale blue in transmitted light
Pyrope garne	1.73 to 1.75	—	—	I	7.25	3.65 to 3.70	greasy to vitreous	Red. Some varieties are very dark, almost black, while others can take tones of purple. Some chromium-rich pyropes are thermochromic, becoming green when heated
Chambersite	1.732–1.744	0.01	Positive	B	7	3.49	Vitreous	Colorless to deep purple
Epidote	1.736–1.770	0.034	Negative	B	6.5	3.25 to 3.50, usually 3.4	Vitreous to resinous	Pistachio-green, yellow-green, greenish black
Pyroxmangite	1.736–1.753	0.017	Positive	B	5 to 6	3.76 (mean)	vitreous, pearly	pink, red, brown
Musgravite	1.739 to 1.735	0.014 to 0.016	—	U	8 to 8.5	3.6 to 3.68	Vitreous	Grey green to green
Periclase	1.737	—	—	I	5	3.55 to 3.60	Vitreous	Colorless, grayish white, yellow, brownish yellow, green, black
Staurolite	1.739–1.750 to 1.747–1.762	0.011 to 0.015	Positive	B	7 to 7.5	3.65 to 3.78	Subvitreous to resinous	Dark reddish brown to blackish brown, yellowish brown, rarely blue; pale golden yellow in thin section
Gahnospinel	1.74 (mean)	—	—	I	8	3.75 (mean)	Vitreous	Green, Blue Dark In Tone, Very Dark Green, Brown To Black
Scorodite	1.74 to 1.81	—	Neg/Pos	B	4	3.22	Sub-Adamantine, Vitreous, Resinous	Green, blue-green, grey, grayish-green, blue, yellow-brown, nearly colorless, violet
Hessonite garnet	1.742 to 1.748	—		I	7.25	3.65	Vitreous	Brown-red
Chrysoberyl	1.75–1.76	—	Positive	B	8.5	3.71 to 3.72	Vitreous	Various shades of green, yellow, brownish to greenish black, may be raspberry-red under incandescent light when chromian; colorless, pale shades of yellow, green, or red in transmitted light
Corundum	1.760-1.768 to 1.77-1.779	0.008 to 0.010	Negative	U	9	3.90 to 4.00	Adamantine to vitreous	Colorless, gray, brown; pink to red, orange, yellow, green, blue, violet; may be color zoned, asteriated mainly grey and brown
Almandine/ pyrope garnet	1.75 to 1.78	— to 0.010	—	I	7.5	3.80 to 3.95	Vitreous	Red
Pyrope/almandine series garnet	1.75 to 1.78	—	—	I	7.5	3.70 to 3.95	Greasy to vitreous	Red. Some varieties are very dark, almost black, while others can take tones of purple. Some chromium-rich pyropes are thermochromic, becoming green when heated
Planchéite	1.752 –1.815	—	—	—	6	3.8	Silky	Blue, greenish blue
Benitoite	1.757 –1.804	0.047	Positive	U	6.5	3.65 to 3.68	Vitreous	Blue, colorless
Rhodolite	1.76	—	—	—	7 to 7.5	3.84 to 0.001 +/-	Greasy to vitreous	Light to dark purplish red through reddish purple
Spinel (Ceylonite)	1.77–1.80	—	—	I	8	3.63 to 3.90	Vitreous	Various; red to blue to mauve, dark green, brown, black
Zircon (low type)	1.78 to 1.81	—	—	I	6	3.90 to 4.10	Greasy to adamantine. Radioactive Zircon has a pitchy luster.	The most common color is dark brown. Also black, gray, light brown, brownish-red, orange, pink, yellow, light blue, light green, light purple white, and colorless. Sometimes multicolored black and dark red, or multicolored with lighter and darker streaks.
reddish orange to red, slightly purplish red to reddish purple and usually dark in tone	1.78 to 1.81	—	—	I	7.5	3.95 to 4.20	greasy to vitreous	reddish orange to red, slightly purplish red to reddish purple and usually dark in tone
Painite	1.787 –1.816	0.029	Negative	U	7.5	4.01	Vitreous	Red, brownish, orange-red
Spessartine garnet	1.79 to 1.81	—	—	I	7.25	4.12 to 4.20	Vitreous	Yellow through red
Monazite	1.795– 1.845	0.05	Positive	B	6	5.2	Resinous, vitreous to adamantine	Reddish brown, brown, pale yellow, pink, green, gray
Gahnite	1.8	—	—	I	7.5 to 8	4.4	Vitreous	Dark green, bluish green, blue to indigo, yellow to brown
Cerussite	1.804– 2.078	0.274	Negative	B	3 to 3.5	6.46 to 6.57	Adamantine, vitreous, resinous	Colorless, white, gray, blue, or green
Yttrium aluminium garnet	1.83	—	—	—	8 to 8.5	4.57 to 4.60	Adamantine, vitreous, resinous	Dark green, bluish green, blue to indigo, yellow to brown
Uvarovite garnet	1.87	—	—	I	7.5	3.77	Vitreous	Green, emerald-green, green-black
Anglesite	1.877–1.894	0.017	Positive	B	2.75 to 3	6.30 to 6.39	Adamantine crystals, dull when massive earthy	Colorless to white, commonly tinted gray; orange, yellow, green, blue, rarely violet
Sphene	1.88– 1.99	0.105	Positive	B	5.5	3.52 to 3.54	Adamantine	Yellow, brown, green, reddish
Demantoid garnet	1.89	—	—	I	6.5	3.82 to 3.85	Vitreous, diamond-like, adamantine	Yellow-green, green to emerald green
Scheelite	1.918–1.934	0.016	Positive	U	4.5 to 5	5.9 to 6.1	Vitreous to adamantine	Colorless, white, gray, brown, pale yellow, yellow-orange, pale shades of orange, red, green; may be compositionally color zoned
Yttrium oxide	1.92	—	—	I	7.5 to 8	4.84	vitreous to subadamantine	usually colorless, but may be pink, red, orange, yellow, green, blue, purple
‘Yttralox’	1.92	—	—	—	6.5	5.3	—	—
Gadolinium gallium garnet	1.92–2.03	—	—	I	6.5	7.05	vitreous to subadamantine	transparent, colorless to light brown or yellow. May also be orange or blue
Zircon (high type)	1.925–1.984	0.059	Positive	U	7 to 7.5	4.67 to 4.70	Vitreous to adamantine; greasy when metamict.	Reddish brown, yellow, green, blue, gray, colorless; in thin section, colorless to pale brown
Rhombic yttrium aluminate	1.938–1.955	0.017	?	B	8	5.35	—	—
Bayldonite	1.95–1.99	0.02	Positive	B	4.5	4.35	Resinous	Green, apple-green
Powellite	1.974–1.984	0.01	Positive	U	3.5	4.34	Adamantine	Straw-yellow, greenish yellow, yellow-brown, brown, colorless, may show blue to black zones
Cassiterite	2.003–2.101	0.098	Positive	U	6.5	6.8 to 7	Adamantine to adamantine metallic, splendent; may be greasy on fractures	Black, brownish black, reddish brown, red, yellow, gray, white; rarely colorless
Zincite	2.013–2.029	0.016	Positive	U	4 to 4.5	5.66	Subadamantine to resinous	Yellow-orange to deep red, rarely yellow, green, colorless
Boléite	2.030–2.050	0.02	Negative	U	3.5	5.05	—	—
Simpsonite	2.06	0.1	—	U	7	6	Vitreous to adamantine	White to cream, yellow to yellow-brown when altered
Euxenite	2.06 to 2.26	—	—	—	6.5	4.7 to 5.0	Brilliant submetallic, waxy to resinous on fractures	Black, brownish black,greenish black
Cubic zirconia	2.09 to 2.18	—	—	I	8 to 8.5	5.98 to 6.06	—	—
Chromite	2.1	—	—	I	5.5	4.1 to 4.9	Submetallic	Black to brownish black; brown to brownish black on thin edges in transmitted light
Phosgenite	2.114–2.140	0.026	Positive	U	3	6.2	Adamantine	Pale yellow to yellowish brown, pale brown, smoky brown, smoky violet; colorless, pale rose, gray, yellowish gray, pale green
Mimetite	2.120–2.135	0.015	Negative	U	3.5	7.0 to 7.25	Resinous, subadamantine	Pale to bright yellow, yellowish brown, yellow-orange, white, may be colorless
Manganot- antalite	2.14–2.22 to 2.19–2.34	0.008 to 0.015	—	B	5.5–6	7.73–7.97	Vitreous	Scarlet-red to dark red.
Samarskite	2.21	—	—	B	5 to 6	4.1 to 6.2	Vitreous - resinous	Black, may have a brownish tint, brown to yellowish brown due to alteration; light to dark brown in transmitted light
Lithium niobate	2.21–2.30	0.9	—	—	6	4.64	—	—
Wulfenite	2.304–2.402	0.098	Negative	U	2.75 to 3	6.7 to 7	Adamantine, resinous	Orange-yellow, yellow, honey-yellow, reddish-orange, rarely colorless, grey, brown, olive-green and even black
Crocoite	2.31–2.66	0.35	Positive	B	2.5 to 3	5.9 to 6.1	Adamantine	Orange, red, yellow
Sphalerite	2.369	—	—	I	3.5 to 4	3.9 to 4.2	Adamantine, resinous, greasy	Brown, yellow, red, green, black.
Zinc blende	2.368–2.371	—	—	I	3.5 to 4	4.08 to 4.10	—	—
Stibiotantalite	2.39–2.46	0.07	Positive	B	5.5 to 6	7.46	Adamantine, Resinous	Yellow to dark brown, reddish or greenish brown
Calcium titanate	2.4	—	—	B	6	4.05	—	—
Strontium titanate	2.41	—	—	I	6	5.13	Adamantine	Usually colorless. Rare earth or transition metals can be added to produce red, orange, yellow, brown, blue.
Diamond	2.42	—	—	I	10	3.52	Adamantine	Typically yellow, brown, or gray to colorless. Less often blue, green, black, translucent white, pink, violet, orange, purple, and red.
Anatase	2.493–2.554	0.061	Negative	U	5.5 to 6	3.82 to 3.95	Adamantine to splendent, metallic	Black, reddish to yellowish brown, dark blue, gray
Greenockite	2.505–2.529	0.024	Positive	U	3.5	4.83 to 4.90	Adamantine to resinous	Honey yellow, citron yellow, orange yellow
Brookite	2.583–2.705	0.122	Positive	B	5.5 to 6	3.87 to 4.08	Submetallic	Deep red, reddish brown, yellowish brown, brown, or black
Rutile (natural and synthetic)	2.62–2.90	0.287	Positive	B	6 to 6.5	4.2	Adamantine to submetallic	Reddish brown, red, pale yellow, pale blue, violet, rarely grass-green; black if high in Nb–Ta
Rutile	2.62–2.90	0.287	Positive	U	6 to 6.5	4.2	Adamantine to submetallic	Reddish brown, red, pale yellow, pale blue, violet, rarely grass-green; black if high in Nb–Ta
Carborundum	2.65–2.69	0.043	Positive	U	9.25	3.17	—	blue-black colour, rainbow sheen
Proustite	2.7 to 3.0	0.3	Negative	U	2 to 2.5	5.57 to 5.64	Adamantine	Scarlet-vermilion
Cuprite	2.85	—	—	I	3.5 to 4	5.85 to 6.15	Adamantine, sub-metallic, earthy	Dark red to conchineal red, sometimes almost black
Hematite	2.94–3.22	—	—	U	6.5	4.95 to 5.16	Metallic to splendent	Metallic gray, dull to bright red
Marble	—	—	—	—	—	2.5 to 2.6	—	—
Nevada wonderstone	—	—	—	—	6 to 6.5	approx. 2.5	—	—
Unakite	—	—	—	—	6 to 7	2.85 to 3.20		—
Magnetop- lumbite	—	—	—	—	6	5.5 to 5.7	Sub-Metallic	Grey-black
Blue pearl	—	—	—	—	—	2.40 to 2.65	—	—
Porcelain	—	—	—	—	4 approx.	2.3	—	—
Bornite	—	—	—	—	3	4.9 to 5.4	Metallic if fresh, iridescent tarnish	Copper red, bronze brown, purple
Conch pearl	—	—	—	—	3.5 to 4	2.84 to 2.89	—	—
Fine pearl	—	—	—	—	—	2.69 to 2.73	—	—
Microlite	—	—	—	I	5.5	5.5	Vitreous - Resinous	Yellowish brown, Reddish brown, Greenish brown, Green, Gray.
Chalcopyrite	—	—	—	—	3.5 to 4	4.2 approx.	Metallic	Brass yellow, may have iridescent purplish tarnish.
Elephant Ivory	1.54	—	—	—	2.5 to 2.75	1.70 to 2.00	—	—
Black clam	—	—	—	—	—	2.20 to 2.66	—	—
Domeykite	—	—	—	—	3.5	7.2 to 7.9	Metallic	Tin-white to steel-gray
Pinite	—	—	—	—	2.5	2.60 to 2.85	—	—
Mollusc shell	—	—	—	—	3.5 to 4	approx. 2.8	—	—
Pentlandite	—	—	—	—	3.5 to 4	5	metallic	Yellowish bronze
Psilomelane	—	—	—	—	7	4.35 approx.	Sub-Metallic, Dull	black with gray pyrolusite bands
Breithauptite	—	—	—	—	4.5 to 5	7.54	Metallic	Pale copper-red, may be with violet tint
Pyrite	—	—	—	—	6.5	4.95 to 5.10	Metallic	Brass yellow - often tarnished to dull brass
Marcasite	—	—	—	—	6 to 6.5	4.85 to 4.90	Metallic	Tin-white on fresh surface, pale bronze-yellow, darkening on exposure, iridescent tarnish
Hippopotamus walrus and narwhal	—	—	—	—	—	1.85 to 1.98	—	—
Cultured pearl	—	—	—	—	—	2.70 to 2.78	—	—
Niccolite	—	—	—	U	5 to 5.5	7.33 to 7.67	metallic	Pale copper red with blackish tarnish. white with strong yellowish pink hue on polished section strongly anisotropic
Calcium	—	—	—	B	6	4.05	—	—
Australian pearl	—	—	—	—	—	2.67 to 2.78	—	—
Cobaltite	—	—	—	I	5.5	6.0 to 6.3	Metallic	Reddish silver white, violet steel gray to black
Algodonite	—	—	—	—	3.5	8.38	Metallic	Gray, silver white, steel gray, tarnishes dull bronze
Kakortokite	—	—	—	—	Varies	2.7 to 2.8	—	—
Barium titanate	2.40	—	—	—	6 to 6.5	5.9	—	—

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