Berill

The mineral beryl is a beryl-aluminium cyclosilicate crystallising in a hexagonal system, the only relatively common mineral of beryl. Its pure form is a gemstone. In nature, beryl can occur in opaque, insignificantly coloured varieties (common beryl) or in transparent, clear, beautifully coloured crystals (precious beryl). The best-known varieties of precious beryl are the green emerald and the blue aquamarine. The most common impurities are potassium, sodium, lithium, caesium, iron and chromium.

It is found in the United States, Russia, Australia, Brazil, Norway.