Facts

Chatoyancy: Tiger’s eye displays a unique reflective quality known as chatoyancy, giving it a silky appearance.

Crocidolite replacement: The fibrous structure of crocidolite (a blue asbestos mineral) is replaced by quartz, which retains the fibres, resulting in the characteristic chatoyant effect.

Major sources: The most notable deposits of tiger’s eye are found in South Africa, Namibia, and Australia.

Polishing: The stone is often polished to enhance its chatoyancy, resulting in a high sheen that highlights the contrasting bands of colour.

Science

Mineral: Quartz
Crystal System: Trigonal
Chemistry: SiO₂
Colour: Typically golden-yellow to brown with chatoyancy but can be blue.
Refractive Index: 1.544 to 1.553
Birefringence: 0.009
Specific Gravity: 2.64 to 2.71
Mohs Hardness: 7

Similar Materials

Pietersite: A related quartz with fibrous inclusions that display a swirling, storm-like pattern.

Hawk’s eye: A blue variety of tiger’s eye, formed in a similar way but retaining the blue-grey hues of crocidolite.

Cat’s eye chrysoberyl: Another gemstone with a cat’s eye effect, though its chatoyancy is more pronounced and typically appears in greenish-yellow.

Treatments

Golden yellow and blue tiger’s eye is mostly untreated, although heat treatment may sometimes be used to create red tiger's eye. Honey coloured tiger's eye is typically bleached. Galaxy tiger's eye and any other tiger's eye colours other than blue and golden-yellow have been dyed.

Synthetics

Synthetic tiger's eye is not common due to the difficulty of replicating the unique chatoyancy effect.

Imitations

Fibre optic glass imitations are used to replicate the chatoyancy of tiger’s eye, but they rarely achieve the same level of character and depth of natural tiger's eye.