Kunzite

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Kunzite (rose-red) on albite (white) Mawi pegmatite, Laghman, Afghanistan

Kunzite is a variety of the mineral spodumene . Other well-known varieties are the green to yellowish-green hiddenite and the yellow triphane . It is used exclusively as a gemstone .

colour

Kunzite are clearly transparent stones, their color fluctuates between almost complete colorlessness to dark purple, whereby a pinkish- red color is created by the addition of manganese . The most beautiful and sought-after Kunzites are deep pink in color with a bluish tinge.

Etymology and history

The Kunzite owes its name to its discoverer, George Frederick Kunz , a famous American gemologist who discovered the Kunzite in 1903 in Pala ( California , USA) as an employee of Tiffany & Co.

Occurrence

The main supplier of good kunzites is the USA , where they are mined in pegmatite rocks together with minerals of the tourmaline group. Other sites are in the region around Minas Gerais in Brazil , in Afghanistan and on the island of Madagascar , some also in Finland .

Use as a gem stone

Kunzite (left) in octagonal and hiddenite (right) in antique cut

For the cut stone, the design of the cut - mainly scissors or step cut , rarely brilliant cut - is of great importance, because spodumene are strongly pleochroic , that is, the colors change in the different directions of the crystalline structure.

Typical of the cut Kunzite is its radiant shine. That is why it gets along so well with diamonds in pieces of jewelry and wins in this combination, which is highly valued in the USA, where kunzite is much better known than in Europe.

Due to its sensitivity to heat and pressure, kunzite causes some problems for jewelry manufacturers . Great care must be taken when grinding and soldering, as the stone loses its color at a temperature of 300 to 400 degrees Celsius and a rapid change in temperature and excessive pressure when grasping it will split it. Exposure to sunlight or strong artificial light over a long period of time bleaches kunzite.

Manipulations and imitations

Despite its sensitivity to heat, kunzite that is too pale or off-color can be improved in color by firing at around 150 ° C. The synthetic kunzite that is often commercially available is actually synthetic corundum of kunzite color.

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. 130 .
  • Bernhard Bruder: Beautified stones. Recognizing imitations and manipulations in gemstones and minerals . Neue Erde, Saarbrücken 2005, ISBN 3-89060-079-4 , p. 78 .

Web links

Commons : Kunzite  - collection of images, videos and audio files