mineral

Eagle Eye Stone (Gray-Blue Tiger's Eye)

Pseudomorph of Quartz after Crocidolite (SiO2)

Hardness: 6.5–7 (Mohs scale); Color: Grayish-blue to dark steel-gray with chatoyant bands; Luster: Silky; Crystal structure: Trigonal/Fibrous; Specific Gravity: 2.64–2.71

Hardness: 6
Color: Grayish-blue to dark steel-gray with chatoyant bands
Luster: Silky

Identified March 25, 2026More mineral →

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Physical properties

Hardness: 6.5–7 (Mohs scale); Color: Grayish-blue to dark steel-gray with chatoyant bands; Luster: Silky; Crystal structure: Trigonal/Fibrous; Specific Gravity: 2.64–2.71

Formation & geological history

Formed through the pseudomorphism process where silica (quartz) replaces the fibrous mineral crocidolite. Unlike golden Tiger's Eye, eagle eye retains its original grayish-blue color because it hasn't undergone the oxidation of iron (limonite) that causes the yellow-gold hues.

Uses & applications

Primarily used in jewelry for beads, cabochons, and ornamental carvings. It is popular in metaphysical healing circles and as a collector's gemstone due to its unique chatoyant 'eye' effect.

Geological facts

This stone is often called 'Hawk's Eye' or 'Eagle Eye'. It exhibits chatoyancy, an optical phenomenon where a band of light reflects off the fibrous inclusions within the stone, mimicking the slit pupil of a bird or cat.

Field identification & locations

Identify by its distinct silky, fiber-like bands that shimmer when moved under light. It is commonly found in South Africa, Australia, and Brazil. Collectors look for high luster and a clear, moving 'eye' or band of light.

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