Emerald

This is the Chalk Emerald, a 37.8 carat emerald from Columbia. It is displayed in the Smithsonian Museum of Natural History. Columbia is the major source of emeralds.

This is the Mackay Emerald Diamond Necklace. It is displayed in the Smithsonian Museum of Natural History.

This is the Hooker Emerald Brooch, containing a 75.47 carat emerald from Colombia.

This is the Inquisition Necklace. It is displayed in the Smithsonian Museum of Natural History.

Emerald has the chemical composition Be₃Al₂(SiO₃)₆ and is classified as a cyclosilicate. It has a hexagonal crystal system 6/m2/m2/m. Its density is 2.67-2.78 and it has an index of refraction in the range 1.566 to 1.602. It's hardness is 7.5 to 8 and its streak color is white.

Some of the world's most famous emerald deposits are in Columbia around hydrothermal sites where they crystalize along fractures in carbonate rocks associated with hot springs. Emerald is a variety of the mineral beryl which is colored green by the inclusion of small amounts of chromium or vanadium.