English: Faceted sunstone from the Tertiary of Oregon, USA. (~1.3 centimeters across at its widest; 5.8 carats)

The gemstone known as "sunstone" is transparent to translucent plagioclase feldspar with mineral inclusions that impart attractive colors. Oregon sunstone is particularly famous because the inclusions are tiny masses of native copper (Cu). In the Oregon sunstone collecting fields, sunstones are relatively large plagioclase phenocrysts in Tertiary-aged, porphyritic, mafic volcanic rocks. Not all Oregon sunstones come from the same volcanic unit. Published dates indicate that the host rocks are Miocene in age - about 15 to 17 million years old.

Locality: Spectrum Mine, east of the northern end of Lake Abert & north of the town of Plush, southern Oregon, USA (vicinity of 42 43' 55.43" North latitude, 119 52' 08.54" West longitude)

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Some info. from: www.gia.edu/doc/1495295555154/GG-FA13-Pay-oregon-sunstone...

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See info. at:

www.highdesertgemsandminerals.com/html/spectrum_sunstone_...