Minerals and Metals in Ancient India v2.c47.18

v2.c47.18

**Aquamarine** : is bluish-green. Heliodor is golden beryl, yellow due to trace of iron. Beryl is harder than hexagonal apatite and green tourmaline. Differs from Chrysoberyl by its form, see Chrysoberyl which is BeAl₂O₄. Beryl can be blue like sapphire (Al₂O₃) just as oriental emerald (Al₂O₃) looks like emerald (beryl) in its green colour.