Tiger's Eye

Hardness: 6.5-7 on Mohs scale. Color: Golden to reddish-brown with chatoyancy (bands of silky luster). Luster: Silky to vitreous. Crystal Structure: Trigonal (cryptocrystalline). Cleavage: None. Specific Gravity: 2.64-2.71

Tiger's Eye is a metamorphic rock that forms when quartz replaces crocidolite asbestos. The crocidolite (a type of blue asbestos) fibers are replaced by quartz, and iron oxides stain the quartz, giving it its characteristic golden-brown color and chatoyant effect. This process typically occurs in low-temperature, high-pressure metamorphic conditions. Its geological age varies, often found in ancient metamorphic rock formations.

Predominantly used as a gemstone in jewelry (beads, cabochons, carvings). Also used for ornamental objects and sometimes for carving larger decorative items. Its unique chatoyancy makes it popular.

Tiger's Eye is known for its captivating optical effect called chatoyancy, or 'cat's eye' effect, which is caused by the parallel intergrowth of quartz crystals and altered amphibole fibers. The Roman soldiers believed wearing Tiger's Eye would provide protection in battle. In some cultures, it is believed to bring good luck, courage, and protection.

In the field, look for its distinctive golden to reddish-brown color and the characteristic silky sheen or 'eye' effect that moves across the surface when viewed from different angles. It is commonly found in South Africa (the primary source), Australia, India, Thailand, and the USA (Arizona). To identify it, observe its chatoyancy under a light source and check its hardness (it can scratch glass). It typically forms in banded iron formations alongside other quartz varieties.