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Fluorescent Specimen
= Radioactive Specimen
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SPHALERITE
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| ACANTHITE pseudo after ARGENTITE San Juan de Rayas Mine, Guanajuato, Mexico Very shiny, metallic black Acanthite (pseudomorph after crystallized Argentite) has formed a free-standing, double terminated intergrowth composed of many stacked, flattened, cubic crystals without matrix or point of attachment. Note the largest, slightly elongated cubic crystal at the top of the specimen—this crystal measures 3/8" tall X 1/4" wide. F. Marshall collection. Specimen size: 1 7/8" long, 3/8" wide, 1/4" thick. Order Item MI-013 Price: $400.
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| TOPAZ with QUARTZ inclusions Shingus Area, Gilgit Division, Pakistan This is an interesting specimen for study, with two water clear, to colorless, to slightly milky individual Topaz crystals grown together in penetration at the base, without rock matrix. Both crystals have very sharp and shiny faces, and both have complex morphology with some faces lightly striated and others showing minor growth hillocks. Several microscopic, colorless, double terminated Quartz crystals are included within the base of one of the Topaz crystals! Magnification of 10-15X is required for best appreciation of this unusual feature. The small white spots shown in one of the accompanying photos are tiny bits of white Albite which were present in the pocket, during the growth of the Topaz crystals. Barry Mercer collection. Overall specimen size: 1 1/2" wide, 1 1/4" tall, and 3/4" deep Individual crystal sizes: 1 1/4" X 3/4" X 5/8", and 1" X 7/8" X 1/2" Order Item MI-1072 Price: $65. |
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