Composition - Beryllium aluminium silicate ; Hardness - 7 1/2
Emerald derives its beautiful green colour from the presence of chromium and vanadium. Emerald are rarely flawless, so stones are often oiled to fill and disguise cracks, hide flaws and enhance colour. To minimize the loss of material the step cut (or emerald cut as it is known) is commonly used, but ancient engravings are known, and cameos ,intaglios and beads can make the best of a flawed stone.
OCCURRENCE
Found in granites, pegmatites and schists as well as alluvial deposits , the finest emerald are from Colombia. Other sources are Austria, India, Australia, Brazil, South Africa, Egypt, the USA, Norway, Pakistan and Zimbabwe.
REMARK
Most emeralds used in historical jewellery would have been from Cleopatra’s mines in Egypt which now yield only poor-quality emeralds.
