Orbicular jasper

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Orbicular jasper from Madagascar Jaspe Orbiculaire de Madagascar 1.jpg
Orbicular jasper from Madagascar

Orbicular jasper is a variety of jasper which contains variably-colored orbs or spherical inclusions or zones. In highly silicified rhyolite or tuff, quartz and feldspar crystallize in radial aggregates of needle-like crystals which provide the basis or seed for the orbicular structure seen in this kind of jasper. [1] The material is quite attractive when polished and is used as an ornamental stone or gemstone.

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Various local or commercial names have been used for the material, such as kinradite, oregonite, ocean jasper and poppy-patterned jasper, depending on the source. Poppy-patterned jasper or poppy jasper is the varietal name for material from several locations, but the most well known is from Morgan Hill, Santa Clara County, California. [2] The trade name ocean jasper is used for a variety found along the intertidal shores of northeast Madagascar. In Nebraska orbicular jasper is found in altered rhyolite beds noted for a variety of jaspers and related agates. In 2017, orbicular jasper was discovered in the Rhodopes of Bulgaria, under the trade name Arda Jasper TM. [3]

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References

  1. "Nebraska". America's Volcanic Past. United States Geological Survey. Archived from the original on 5 March 2014. Retrieved 28 February 2014.
  2. Hohmann, James (12 November 2006). "City pride built on poppy jasper". San Jose Mercury News. Archived from the original on 9 March 2021. Retrieved 28 February 2014.
  3. "A Greek discovered a deposit of rare jasper in the Momchilgrad region". World Today News. 27 December 2021. Archived from the original on 31 December 2021. Retrieved 29 September 2023.