PREHNITE and EPIDOTE Crystal Mineral Specimen Green Crystal ATLAS MTS MOROCCO

Description: This specimen weighs 41.67 grams. It measures 40 mm x 33 mm x 25 mm. I offer a shipping discount for customers who combine their payments for multiple purchases into one payment! The discount is regular shipping price for the first item and just 50 cents for each additional item! To be sure you get your shipping discount just make sure all the items you want to purchase are in your cart. Auctions you win are added to your cart automatically. For any "buy it now" items or second chance offers, be sure to click the "add to cart" button, NOT the "buy it now" button. Once all of your items are in your cart just pay for them from your cart and the combined shipping discount should be applied automatically. I offer a money back guarantee on every item I sell. If you are not 100% happy with your purchase just send me a message to let me know and I will buy back the item for your full purchase price. Hi there, I am selling this lovely prehnite and epidote mineral specimen. This comes from the Atlas Mountains of Morocco. If you have any questions, do not hesitate to ask me. Have fun bidding, thanks so much for visiting my auction and have a great day!Here's some info about this mineral from wikipedia: Prehnite ArticleTalkReadEditView historyFrom Wikipedia, the free encyclopediaPrehnitePrehnite - Southbury, Connecticut, USA.jpgGeneralCategorySilicate mineralFormula(repeating unit)Ca2Al(AlSi3O10)(OH)2IMA symbolPrh[1]Strunz classification9.DP.20(Inosilicate transitional to phyllosilicate)Dana classification72.1.3.1(Phyllosilicate)Crystal systemOrthorhombicCrystal classPyramidal (mm2)(same H-M symbol)Space groupP2cmIdentificationColorColorless to gray to yellow, yellow-green or whiteCrystal habitGlobular, reniform to stalactiticTwinningFine lamellarCleavageDistinct on [001]TenacityBrittleMohs scale hardness6 - 6.5LusterVitreous - pearlyStreakWhiteDiaphaneitySemi-transparent to translucentSpecific gravity2.8 - 2.95Optical propertiesBiaxial (+)Refractive indexnα = 1.611 - 1.632nβ = 1.615 - 1.642nγ = 1.632 - 1.665Birefringenceδ = 0.021 - 0.033Dispersionweak r > vUltraviolet fluorescenceFluorescent, short UV=blue white mild peach, long UV=yellowReferences[2][3][4][5][6]Prehnite is an inosilicate 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 often 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, including those found at the Jeffrey Mine in Asbestos, Quebec, Canada. Prehnite is brittle with an uneven fracture and a vitreous to pearly luster. 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, pink or white. In April 2000, rare orange prehnite was discovered in the Kalahari Manganese Fields, South Africa. Prehnite is mostly translucent, and rarely transparent. Though not a zeolite, prehnite is found associated with minerals such as datolite, calcite, apophyllite, stilbite, laumontite, and heulandite 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 was first described in 1788 for an occurrence in the Karoo dolerites of Cradock, Eastern Cape Province, South Africa.[4] It was 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.[4] It is used as a gemstone.[7] Extensive deposits of gem-quality prehnite occur in the basalt tableland surrounding Wave Hill Station in the central Northern Territory, of Australia.[8]

Price: 19.99 USD

Location: Tucson, Arizona

End Time: 2024-12-09T00:49:35.000Z

Shipping Cost: 5.95 USD