6/20/2023 0 Comments Red tiger eye gemstone![]() They found no evidence that tiger’s eye was a pseudomorph, but rather proposed it was formed through a discontinuous crack-seal mechanism. This theory was accepted as fact until the early 2000’s when some scientists studying pseudomorphs put a piece of South African tiger’s eye under a scanning electron microscope. The stone then weathered/rusted causing the surfaces of the remaining crocidolite to become coated in iron oxides creating the golden color. They believed that quartz replaced most of the crocidolite, and the remaining asbestos provided the bluish color. Since the 1870’s, geologists believed that tiger's eye was a pseudomorph where quartz replaced crocidolite - a blue form of asbestos. Large block of Tiger's Eye found during mining near Mt. Brockman where a 6 mile long, ridge of hills has produced extremely nice material from a number of small deposits. The area is iron ore which was deposited around 2.7 billion years ago and Tiger’s Eye is found in a few small areas within these deposits. It is mined from the remote Hamersley Ranges of the Pilbara region. Western Australia is another important source of Tiger’s Eye and is where some of the exotic varieties such as Marra Mamba are found. More information can be found here and here.įun Fact: Before the discovery of large deposits in South Africa, Tiger’s Eye was considered almost as valuable as gold. The terrain in mountainous and the mining operations are fairly small scale. The tiger's eye is unevenly distributed and occurs as lenses of various sizes, interbedded in gently folded metasedimentary rocks of mostly banded iron formation (BIF). The vast majority of Tiger Eye is mined in South Africa near the town of Prieska in the Northern Cape Province. It can also be found in Burma, India, Namibia, Brazil, Canada, and several places in the United States. Nearly all of the Tiger’s Eye on the market comes from either South Africa or Western Australia. Tiger’s Eye is found within iron ore formations since staining from iron oxides is needed to create its color. If the fibers have not been stained with iron oxides the stone will instead take on a blue color. While Tiger’s Eye’s chatoyance is caused by fibers of crocidolite, the golden/red/brown color is due to iron oxides (primarily Limonite) staining the surface of these fibers. The effect can be likened to the sheen off a spool of silk and can be enhanced by polishing the stone. Within the bands in Tiger’s Eye these fibers are aligned in the same direction and the light is reflected perpendicular to the direction of the fibers. ![]() This effect is caused by the light reflecting off of microscopic fibers of crocidolite (a blue form of asbestos) within the stone. ![]() Tiger’s Eye or Tiger Eye has a stunning chatoyant effect where the alternating bands of color appear to reverse as the stone or light source is moved. What Gives Tiger’S Eye It’S Fascinating Color Play? ![]()
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