metamorphic
Tiger Iron
Tiger Iron (Hematite, Red Jasper, and Chert/Tiger's Eye composite)
Hardness: 7 Mohs; Color: Alternating bands of gold, black (metallic), and red (the specimen shown is primarily the dark hematite and yellow tiger's eye phases); Luster: Silky to metallic; Crystal structure: Trigonal/Hexagonal; Cleavage: None; Specific gravity: 2.64-2.71.
- Hardness
- 7 Mohs
- Luster
- Silky to metallic
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Physical properties
Hardness: 7 Mohs; Color: Alternating bands of gold, black (metallic), and red (the specimen shown is primarily the dark hematite and yellow tiger's eye phases); Luster: Silky to metallic; Crystal structure: Trigonal/Hexagonal; Cleavage: None; Specific gravity: 2.64-2.71.
Formation & geological history
Formed during the Precambrian era (over 2 billion years ago). It is a banded iron formation (BIF) consisting of alternating layers of silver-grey hematite, red jasper, and golden tiger's eye, which have been compressed and metamorphosed over millions of years.
Uses & applications
Predominantly used for ornamental purposes, lapidary art, jewelry (cabochons and beads), and as a popular collector's specimen due to its unique appearance and high polish.
Geological facts
Tiger Iron is considered one of the oldest geological materials on Earth, representing a time when the atmosphere and oceans were transitioning from anaerobic to aerobic states, causing iron to precipitate into layers on the ocean floor.
Field identification & locations
Identify by its heavy weight (due to iron content) and distinct structural bands of metallic grey and golden quartz. It is almost exclusively found in the Ord Ranges of Western Australia and South Africa.
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