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|Dimensions (mm)||76.2 x 44 x 26mm|
|Weight (carats)||807.961 carats|
Prehnite Apophylite rare mineral
3 inches long 5.8 oz. Prehnite Apophylite rare mineral specimen
223zeolite10 and 11
The name apophyllite refers to a specific group of phyllosilicates, a class of minerals that also includes the micas. Originally, the group name referred to a specific mineral, but was redefined in 1978 to stand for a class of minerals of similar chemical makeup that comprise a solid solution series, and includes the members apophyllite-(KF), apophyllite-(KOH), and apophyllite-(NaF). The name apophyllite is derived from the Greek ?p?F?????? apophylliso, meaning “it flakes off”, a reference to this class’s tendency to flake apart when heated, due to water loss. These minerals are typically found as secondary minerals in holes in basalt or other igneous rocks. They can also be called “fisheye stone”. A recent change in the nomenclature system used for this group was approved by the International Mineralogical Association, removing the prefixes from the species names and using suffixes to designate the species.
Though relatively unfamiliar to the general public, apophyllites are fairly prevalent around the world, with specimens coming from some of the world’s most well-known mineral localities. These localities include: Poona, India; the Harz Mountains of Germany, Mont Saint-Hilaire in Canada, and Kongsberg, Norway, with other locations in Scotland, Ireland, Brazil, Japan, and throughout the United States.
Prehnite is a phyllosilicate of calcium and aluminium with the formula: Ca2Al(AlSi3O10)(OH)2. Limited Fe3+ substitutes for aluminium in the structure. Prehnite crystallizes in the orthorhombic crystal system, and most oftens forms as stalactitic or botryoidal aggregates, with only just the crests of small crystals showing any faces, which are almost always curved or composite. Very rarely will it form distinct, well individualized crystals showing a square-like cross-section, like those found at the Jeffrey Mine in Asbestos, Quebec, Canada. It is brittle with an uneven fracture and a vitreous to pearly lustre. Its hardness is 6-6.5, its specific gravity is 2.80-2.90 and its color varies from light green to yellow, but also colorless, blue or white. In April 2000, a rare orange Prehnite was discovered at the famous Kalahari Manganese Fields in South Africa. It is mostly translucent, and rarely transparent. Though not a zeolite, it is found associated with minerals such as datolite, calcite, apophyllite, stilbite, laumontite, heulandite etc. in veins and cavities of basaltic rocks, sometimes in granites, syenites, or gneisses. It is an indicator mineral of the prehnite-pumpellyite metamorphic facies. It is the first mineral to be named after someone, and was first described in 1789 for an occurrence in Haslach, Harzburg and Oberstein, Germany, and named for Colonel Hendrik Von Prehn (1733–1785), commander of the military forces of the Dutch colony at the Cape of Good Hope from 1768 to 1780. Extensive deposits of gem quality Prehnite occur in the basalt tableland surrounding Wave Hill Station in the central Northern Territory, of Australia.
* USE DISCRIMINATION * As always we emphasize that the information * regarding the metaphysical properties * of stones is intuitive, * and not scientifically verified. * This field is one of speculation and exploration, * and individuals are encouraged to use discrimination * to determine what is true for them. * we cannot guarantee any results * with any stone or jewelry item. * We advocate individual responsibility * for one’s exploration of these ideas, * and we do not advocate the use of stones * as a substitute for medical or psychological care. * Our stones are not intended to treat or cure any disease or ailment.
|Starts||27th Feb 2018 3:04pm PST|
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