Orbicular jasper

{{Short description|Variety of the mineral jasper}}

{{Use dmy dates|date=October 2024}}

File:Jaspe Orbiculaire de Madagascar 1.jpg

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.{{cite web |title=Nebraska |url=http://vulcan.wr.usgs.gov/LivingWith/VolcanicPast/Places/volcanic_past_nebraska.html |work=America's Volcanic Past |publisher=United States Geological Survey |accessdate=28 February 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140305060338/https://vulcan.wr.usgs.gov/LivingWith/VolcanicPast/Places/volcanic_past_nebraska.html |archive-date=5 March 2014}} 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, 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.{{cite news |last=Hohmann |first=James |title=City pride built on poppy jasper |url=http://www.mercurynews.com/ci_5219104 |accessdate=28 February 2014 |newspaper=San Jose Mercury News |date=12 November 2006 |url-status=live |archive-url=https://web.archive.org/web/20210309130402/https://www.mercurynews.com/2007/02/13/city-pride-built-on-poppy-jasper/ |archive-date=9 March 2021}} The trade name Ocean Jasper is used for a variety found along the intertidal shores of northeast Madagascar.{{cite web |title=OCEAN JASPER Trademark Application of Enter the Earth, Inc. |website=Serial Number 90525918 :: Justia Trademarks |date=21 September 2021 |url=https://trademarks.justia.com/905/25/ocean-90525918.html |access-date=31 October 2024}}{{cite book |last=Green |first=J.A. |title=The Crystal Collector: How to build a lifelong collection of precious stones |publisher=David & Charles |year=2024 |isbn=978-1-4463-1338-1 |url=https://books.google.com/books?id=Xpr8EAAAQBAJ&pg=PT14 |access-date=31 October 2024 |page=14}} In Nebraska orbicular jasper is found in altered rhyolite beds noted for a variety of jaspers and related agates.