Tiger's Eye

Tiger's eye is a golden- to reddish-brown variety of quartz famous for its chatoyancy—a shimmering, mobile band of light that sweeps across the polished surface like a cat's eye. The effect comes from parallel fibrous structures within the stone reflecting light.

It forms when quartz pseudomorphs (replaces) the fibrous blue asbestos mineral crocidolite while preserving its fibrous texture. The iron oxide left behind gives the classic gold-brown color.

Related stones include hawk's eye (blue-gray, less altered) and red tiger's eye (often heat-treated). All are popular, durable, and affordable gemstones for cabochons and beads.

Tiger's eye forms through a replacement (pseudomorph) process in metamorphic settings. Veins of fibrous crocidolite (a blue asbestos amphibole) are gradually replaced by silica as quartz infiltrates, preserving the parallel fiber alignment.

As the iron in the crocidolite oxidizes, it stains the quartz golden brown. Where the original blue color is partly preserved, the result is hawk's eye; full alteration yields golden tiger's eye.

The most famous deposits are in South Africa (Griqualand West), with additional sources in Western Australia, India, and Brazil.

• Optical effect: The defining feature is chatoyancy—a bright, silky band of light that moves as you tilt the stone.
• Color: Golden-brown, often with darker brown stripes; bluish in hawk's eye.
• Hardness: 6.5-7; scratches glass.
• Luster: Silky to vitreous when polished; fibrous structure visible.

Look-alikes: Imitation 'tiger's eye glass' (sometimes called cat's eye glass) shows a too-perfect single eye and parallel sides; real tiger's eye has a wavy, fibrous chatoyant band and natural color variation. Pietersite is a related but more chaotic, swirling stone.

Tiger's eye is a popular and affordable gemstone, cut as cabochons, beads, and cameos for rings, bracelets, and pendants, and carved into figurines and ornamental objects. The chatoyant band makes it visually striking despite its low cost.

Value depends on the strength and sharpness of the chatoyancy, even color, and good polish. Red and multicolor pieces are sought after.

In metaphysical traditions it is associated with courage, focus, and protection—cultural beliefs without scientific basis.