May-Emerald

Colour	Green
Formula	Be3Al2(SiO3)6
Group	Silicates
Uses	Jewellery
Origins	Forms in granites and pegmatite rocks
Locations	Columbia, Brazil Colourless

Emerald is a variety of beryl. It is green due to the presence of chromium. Perfect specimens are very rare and valuable. Imperfections can be disguised by cutting it a certain way or in some cases filling it with oil.

It is fairly hard (7.5-8 on the mohs scale). Nearly all emeralds from Brazil contain calcite or pyrite.