Black Tiger's Eye

Black tiger's eye is normally coloured by dyeing, so it has no documented natural deposit of its own. Its base material, tiger's eye, comes mainly from South Africa; other recorded sources include Western Australia, India, Myanmar, Sri Lanka, Brazil, China, Namibia and the United States. Where the stones are dyed is not documented in the sources consulted; Pascle gives South Africa and Namibia as origins of its material.

Black tiger's eye looks almost black in dim light and shows a faint chatoyant band when lit, keeping the fibrous structure of tiger's eye. The gemmologist R. Webster noted that many tiger's eye cabochons are stained and that vivid greens, blues and blacks are obviously stained. GIA notes that a qualified gemologist can detect dyed gems in most cases; whether a particular black stone is dyed should be settled by testing, not by appearance alone. Fibre-optic glass can imitate the chatoyancy of these materials but is a man-made product.

Because the colour usually comes from dye, keep the stones away from solvents such as alcohol or acetone, which can remove many dyes, and from prolonged sunlight, which can make some dyes fade. Jewelers commonly recommend cleaning tiger's eye only with a polishing cloth rather than alcohol, steam or an ultrasonic cleaner, and note that it chips or breaks more readily than many gems when struck.

The Japanese retailer Pascle says that black tiger's eye shares the meanings it gives to all colours of tiger's eye: because the "tiger's eye" was traditionally thought to see through everything, the stone is said to sharpen its wearer's insight, and the retailer associates it with luck in work and money.