BERYLLIUM ALUMINUM SILICATE

gemstone; green or blue; chief ore for beryllium; hexagonal, a=0.9188 nm, c=0.9189 nm [CIC73] [KIR78]

Beryl, Be3Al2Si6O18, is called aquamarine when pale green or blue from the presence of Fe, emerald when dark green from Cr or at times V, and morganite or red beryl when pink or red, respectively, from Mn. Only synthetic emerald is in commercial production.

(i) a low mass density;
(ii) low refractive indices;
(iii) dichroism;
(iv) a low birefringence.

A mineral, 3BeO.Al2O3.6SiO2, used as a source of beryllium. There are several varieties including the gemstones emerald (colored green by traces of chromium oxide) and aquamarine (a bluegreen color).

Confirmed carcinogen withexperimental carcinogenic, neoplastigenic, andtumorigenic data. When heated to decomposition it emitstoxic fumes of BeO.