Tiger Eye is a metamorphic rock composed mainly of quartz with parallel inclusions of fibrous crocidolite, which have been replaced by silica. This flat, polished specimen showcases the material’s distinctive golden to reddish-brown bands and chatoyancy-- a light-reflective optical effect that gives the surface a silky, shifting appearance.
Features:
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Composition and Formation: Tiger Eye forms when quartz replaces fibrous blue crocidolite in a process known as pseudomorphism, preserving the fibrous texture while creating a hard, durable stone.
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Optical Properties: The shimmering, banded appearance-- known as chatoyancy or “cat’s eye” effect—occurs due to the alignment of microscopic fibers within the quartz.
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Geologic Context: Commonly found in South Africa and Western Australia, Tiger Eye is often associated with banded iron formations and ancient metamorphic rock zones.
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Educational Use: This polished sample is ideal for illustrating mineral replacement, light interference in crystal structures, and metamorphic processes.
