CATALOGUE OF GEMS AND PRECIOUS STONES. 211 



IV. Color green — Continued. 



A. Transparent or nearly so — Continued. 



(6) Hardness 8 to 7; scratched by corundum but not by quartz. 



1. Sp.gr. 3.7; color yellow-green, in artificial light red. Chrysoberyl, alexandrite. 



2. Sp. gr. 3.2; color pale brown-green or yellow-green Andalusite. 



3. Sp. gr. 3.1; pleochroic, pale to deep green Tourmaline. 



4. Sp. gr. 2.7; color pale blue-green, faintly pleochroic Beryl. 



5. Sp. gr. 2.7; color deep green, moderately pleochroic Beryl, emerald. 



6. Sp. gr. 2.65; color pale, cloudy green, not pleochroic Quartz, prase. 



(The rare green-colored varieties of euclase, topaz, and zircon belong here.) 

 (c) Hardness less than 7; scratched by quartz. 



1. Sp. gr. 3.8; color deep yellow-green; isotropic Garnet, demantoid. 



2. Sp. gr. 3.5; pleochroic, deep green-yellow to brown Epidote. 



3. Sp. gr. 3.4; pleochroic, yellow-green to green-yellow Titanite, sphene. 



4. Sp. gr. 3.4; faintly pleochroic; color green-yellow Chrysolite, peridot. 



5. Sp. gr. 3.3; not pleochroic; color pale green Pyroxene, diopside. 



6. Sp. gr. 3.2; pleochroic, pale to deep green Spodumene, hiddenite. 



7. Sp. gr. 2.5; color dark brown-green; isotropic Obsidian, moldavite. 



8. Sp. gr. mostly below 3; isotropic Glass (artificial). 



(The rarely used minerals dioptase and prehnite and the rare green-colored 

 varieties of apatite, enstatite, fluorite, and vesuvianite belong here.) 



B. Opaque or nearly so. 



(a) Hardness greater than 6; scratch microcline. 



1. Sp. gr. 3.3; luster rather vitreous; color yellow-green. 



Vesuvianite, californite. 



2. Sp. gr. 3.3; luster rather greasy; color green or greenish gray. .Jade (jadeite). 



3. Sp. gr. 2.6; luster rather waxy; color pale blue-green. 



Chalcedony, chrysoprase. 



4. Sp. gr. 2.6; luster rather dull; color dark blue-green. . .Chalcedony, plasma. 



(When plasma is spotted with red it is known as bloodstone.) 



(b) Hardness 6 or less; do not scratch microcline. 



1. Sp. gr. 4; color intense green; luster rather silky Malachite. 



2. Sp. gr. 3, color green or greenish gray; luster greasy Jade (nephrite). 



3. Sp. gr. 2.8; color pale blue-green; luster rather waxy Turquoise. 



4. Sp. gr. 2.6; color pale or deep green; luster greasy Serpentine. 



5. Sp. gr. 2.6; color blue-green, streaky; luster vitreous. 



Microcline, amazonstone. 



6. Sp. gr. 2.6; color green-blue-green: luster waxy Variscite. 



7. Sp. gr. mostly below 3; isotropic; luster vitreous Glass (artificial). 



(Several little-used minerals belong here, such as calamine (copper- 

 stained), chlorastrolite, chrysocolla, fuchsite, smithsonite (copper- 

 stained), etc.) 



V. Color yellow. 



A. Transparent or nearly so. 



(a) Hardness 9 or greater; not scratched by corundum. 



1. Scratches corundum surface; not scratched by diamond point Diamond. 



2. Does not scratch corundum surface Corundum (oriental topaz). 



(b) Hardness 8 to 7; scratched by corundum but not by quartz. 



1. Sp. gr. very high, 4.5 Zircon, hyacinth. 



2. Sp. gr. high, 3.7 Chrysoberyl. 



3. Sp. gr. fairly high, 3.5 Topaz. 



4. Sp. gr. medium, 2.7 Beryl, golden. 



5. Sp. gr. 2.65 Quartz, citrine. 



(The rare yellow varieties of chrysolite, danburite, garnet, spinel, and 

 tourmaline belong here.) 



