Orbicular jasper

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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.

Various local or commercial names have been used for the material, such as kinradite, oregonite, owyhee jasper, 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.

Also orbicular jasper (like Ocean jasper) has been found in a new location in Bulgaria in early 2017 by Nikolaos Dafnis and Asimina Sklari and they gave the trade name Bulgarian "Orbicular Arda Jasper TM"



Gallery[]

  • Unpolished poppy jasper, Morgan Hill

  • Madagascar orbicular jasper (detail)

  • Bulgarian Orbicular Arda Jasper TM

  • Bulgarian Orbicular Arda Jasper TM

Bulgarian "Orbicular Arda jasper TM"

References[]

  1. ^ "Nebraska". America's Volcanic Past. United States Geological Survey. Retrieved 28 February 2014.
  2. ^ Hohmann, James (12 November 2006). "City pride built on poppy jasper". San Jose Mercury News. Retrieved 28 February 2014.

External links[]

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