GEMSTONES & MINERALS
Wholesale minerals, crystals, gemstones & fossils

Tigers eye is a rare form of black quartz  which has yellow and golden brown stripes. It is a popular gemstone  that it is also used in ornamentation. Tigers eye is a gemstone that is fibrous in structure and predominantly black in colour. It is stained by iron oxide and is what gives it its distinctive tigers stripe colouration.

Tigers eye is variety of chatoyant quartz. Chatoyant means "twinkling", but with a changeable sheen, (lustre).' Chatoyancy' is another name for the cats eye effect that occurs in several  different gemstones such as chrysoberyl.

Cats eye was in general are optical effects that are caused by fibrous inclusions - particularly inclusions of the mineral crocidolite (also known as blue asbestos) and hornblende within the bodies of some minerals.

Tigers eye,  however, is always a form of quartz that gets its distinctive yellow and golden brown stripes from inclusions of iron oxide.

The mineral that finally becomes Tigers by begins life as crocidolite, some of which is replaced by quartz. Crocidolite contains a certain amount of iron that can become oxidated or hydrated by exposure to it and water. The when these chemical reactions take place a new chemical is formed called iron hydroxide.

The mineral made up of these chemicals is called limmonite which is a yellow colour. When the level of iron in the crocidolite is high enough, the yellow colouration becomes visible in the body of the Tigers I, where tiny particles of limmonite are spread out among the fibres of the quartz.

Another variety of chatoyant quartz is called Hawk's eye rough. Hawk's eye rough forms when crocidolite combines with quartz in the same manner that is described above, but the blue -- grey or blue -- green colour of the original quartz remains visible in the final product.

Tigers eye is a member of the silicate group of minerals and crystals. It is a form of quartz, and like all other varieties of that mineral, it is an oxide of the non-metallic element silicon. Silicon and oxygen are the two most abundant elements on the Earth and silicon alone makes up 27,7% of the weight of the earth's crust.

Tigers eye is quite a rare form of quartz. It gets its characteristic fibrous appearance through substituting its self in place of crocidolite (Crocidolite is itself a variant of the mineral riebeckite, a complex silicate belonging to the amphibole group, which contains the metallic element iron. It is also know as blue asbestos).

The colouring in tigers eye derives from addition of iron from the crocidolite to the oxygen that is already present in the basic quartz structure of tigers eye.

By heating tigers eye it is possible to cause a chemical reaction in the limonite particles and change them to the reddish haematite. The resulting mineral is called ox-blood and if this is placed in hydrochloric acid, the colouring will fade to a grey- green colour that resembles the precious cat's eye variety of quartz.

In most other aspects, the chemistry of tigers eye is the same as that of quartz.

Although small quantities have been found in Australia, Burma, India, and Brazil, South Africa is responsible for practically all the tigers eye production in the world.