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Porphyry Porphyry is a variety of igneous rock consisting of large-grained crystals, such as feldspar or quartz, dispersed in a fine-grained feldspathic matrix or groundmass. The larger crystals are called phenocrysts. In its non-geologic, traditional use, the term "porphyry" refers to the purple-red form of this stone, valued for its appearance. The term "porphyry" is from Greek and means "purple". (source: Wikipedia) Photo by Michael Marcotte Return to List Back to Michael's Hobbies page Back to Michael Marcotte's HomePage |
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