Tiger eye
Tiger's eye is a microcrystalline, golden brown to golden yellow striped variety of the mineral quartz . The translucent to opaque aggregates usually have a clearly visible fibrous structure and show a fat to silk-like sheen on the surfaces .
Tiger's eye is used exclusively as a gemstone , which is processed in a smooth cut and shows a billowing shimmer, called chatoyance or "cat's eye effect".
Education and Locations
Tiger's eye goes from Falkenauge indicates a parallelfaserigem by incorporation of crocidolite - or similarly shaped hornblendes bluish quartz variety. The pseudomorphism of crocidolite to quartz with additional iron deposition results in tiger's eye. The parallel alignment of the crystal fibers also ensures the well-known light effect of chatoyance. Due to the special educational conditions, hawk's eye and tiger's eye are often found next to each other or grown together at the same site.
Tiger eyes are mainly found in South Africa and Western Australia , as well as in China , India , Canada , Myanmar , Namibia , Ukraine and the United States (USA) as a gap filling in quartz rock, with the fibers of the tiger's eye being perpendicular to the boundary of the gap .
The largest known specimen of a tiger's eye (150 kg, 2 m long) has been in the possession of the Mineralogical Museum of the University of Bonn since 2008 .
In Namibia and China, a breccia-like mixture of falcon's eye and tiger's eye was also discovered, which became known under the trade name Pietersite .
Use as a gem stone
Tiger's eye is mostly offered in the form of cabochons in various designs, but also spherical for necklaces or freely cut for handicrafts. Highly curved cabochons show a wandering streak of light, which is called chatoyance and is reminiscent of the slit pupil of a cat.
Manipulations and imitations
By burning tiger eye receives a strong copper-red color, which then by quenching in alcohol to the Violette can come into play. Red tiger's eye cannot be found in nature and is therefore always burned.
When cooked in strong acid, tiger's eye will lose its color and turn gray. In this form it is occasionally offered as an imitation of chrysoberyl cat's eyes or cat's eye quartz . Even honey-colored tiger eyes sometimes serve as imitations of chrysoberyl.
Due to the similarity in color, there is a risk of confusion with tiger iron and the so-called “tiger jasper ”.
Esoteric
Esotericists use tiger's eye as a healing stone against headaches, testicular diseases and sciatica symptoms, among other things. However, there is no scientific evidence of such effects. As a “planet stone” it is assigned to Mercury and Mars (according to Ahlborn 1996) and as a “month stone” to the month of November . As an amulet stone , it is said to bring luck to members of the Gemini zodiac .
See also
literature
- Walter Schumann: Precious stones and gemstones. All kinds and varieties. 1900 unique pieces . 16th revised edition. BLV Verlag, Munich 2014, ISBN 978-3-8354-1171-5 , pp. 140, 240 (Pietersite) .
- Bernhard Bruder: Beautified stones. Recognizing imitations and manipulations in gemstones and minerals . Neue Erde, Saarbrücken 2005, ISBN 3-89060-079-4 , p. 102 .
- Jaroslav Bauer, Vladimír Bouška: Gemstone Guide . Verlag Werner Dausien, Hanau / Main 1993, ISBN 3-7684-2206-2 , p. 126 .
Web links
- Mineral Atlas: Tiger's Eye (Wiki)
- Tiger's Eye. In: mindat.org. Hudson Institute of Mineralogy, accessed April 21, 2018 .
Individual evidence
- ↑ aheuser: Valuable gem . The largest gemstone in Germany is in the Mineralogical Museum of the University of Bonn. In: steinmann.uni-bonn.de. Mineralogical Museum of the University of Bonn, 2008, accessed on April 21, 2018 .
- ^ Precious stone etiquette by Prof. Leopold Rössler. Tiger eye. In: beyars.com. BeyArs GmbH, accessed on April 21, 2018 .