A very hard mineral (8.5 on the mohs scale-only diamond and corundum are harder). It is usually yellow/green but can also be brown. It is an oxide with the formula BeAl2O4 (contains beryllium and aluminium). It may contain impurities and derives it's yellow colour from small amounts of iron.

Varieties of Chrysoberyl include Alexandrite and Cats Eye. Alexandrite has a unique characteristic in that it appears green in daylight and red under artificial light.

Chrysoberyl forms in mica schists and may be found in alluvium (sediments deposited by rivers). It can be found in Sri Lanka and Brazil. (The best Alexandrite samples are from the Urals, Russia)

It derives it's name from the words chrysos (Greek for golden) and beryllos (due to it's beryllium content).

SODALITE

It is usually blue but may also be green, white or grey. It's name refers to it's sodium content.

It is a silicate with the chemical formula Al3Si3O12Cl and may contain calcium. It is moderately hard (5-5.5 on the mohs scale).

Sodalite is a component of Lapis Lazuli and may often be confused with this although it does not contain pyrite. The best specimens are very rare and therefore very valuable.

It is mostly found in igneous rocks in countries such as Bolivia, Brazil, Russia and Canada.

Sodalite from Canada is known as Princess Blue.