PRISMATIC EPIDOTE Gemmy Crystal Mineral Specimen Green Crystal MOROCCO

Description: This specimen weighs 11.43 grams. It measures 36 mm x 36 mm x 11 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 really nice epidote mineral specimen. It is really beautiful. This comes from Imilchil in the Atlas Mountains of Morocco. The minerals from there are very green and gorgeous! Have fun bidding, thanks so much for visiting my auction and have a great day!Here's some info about this mineral from wikipedia: EpidoteFrom Wikipedia, the free encyclopediaEpidoteEpidote-119736.jpgEpidote crystals – Deposit topotypeGeneralCategorySorosilicatesFormula(repeating unit) {Ca2}{Al2Fe3+}[O|OH|SiO4|Si2O7]Crystal systemMonoclinicCrystal classPrismatic (2m)(same H-M symbol)Space groupP21/mIdentificationColorPistachio-green, yellow-green, greenish blackCrystal habitPrismatic with striations, fibrous, massiveTwinningOn [100]Cleavage{001} perfect and {100} imperfectFractureFlat regular to unevenMohs scale hardness6–7Luster Vitreous to resinousStreakGreyish whiteDiaphaneityTransparent to nearly opaqueSpecific gravity 3.3–3.6Optical propertiesBiaxial (-)Refractive indexnα = 1.715–1.751nβ = 1.725–1.784nγ = 1.734–1.797Birefringenceδ = 0.019–0.046PleochroismStrongReferences[1][2][3]Epidote is a calcium aluminium iron sorosilicate mineral. Contents [hide] 1Description1.1 Related species2See also3References4External linksDescription[edit]Well developed crystals of epidote, Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH), crystallizing in the monoclinic system, are of frequent occurrence: they are commonly prismatic in habit, the direction of elongation being perpendicular to the single plane of symmetry. The faces are often deeply striated and crystals are often twinned. Many of the characters of the mineral vary with the amount of iron present for instance, the color, the optical constants, and the specific gravity. The color is green, grey, brown or nearly black, but usually a characteristic shade of yellowish-green or pistachio-green. It displays strong pleochroism, the pleochroic colors being usually green, yellow and brown. Clinozoisite is green, white or pale rose-red group species containing very little iron, thus having the same chemical composition as the orthorhombic mineral zoisite. The name, due to Haüy, is derived from the Greek word "epidosis" (ἐπίδοσις) which means "addition" in allusion to one side of the ideal prism being longer than the other. Epidote from AlaskaEpidote is an abundant rock-forming mineral, but one of secondary origin. It occurs in marble and schistose rocks of metamorphic origin. It is also a product of hydrothermal alteration of various minerals (feldspars, micas, pyroxenes, amphiboles, garnets, and others) composing igneous rocks. A rock composed of quartz and epidote is known as epidosite. Well-developed crystals are found at many localities: Knappenwand, near the Großvenediger in the Untersulzbachthal in Salzburg, as magnificent, dark green crystals of long prismatic habit in cavities in epidote schist, with asbestos, adularia, calcite, and apatite; the Ala valley and Traversella in Piedmont; Arendal in Norway; Le Bourg-d'Oisans in Dauphiné; Haddam in Connecticut; Prince of Wales Island in Alaska, here as large, dark green, tabular crystals with copper ores in metamorphosed limestone. The perfectly transparent, dark green crystals from the Knappenwand and from Brazil have occasionally been cut as gemstones. Related species[edit]Belonging to the same isomorphous group with epidote are the species piemontite and allanite, which may be described as manganese and cerium epidotes respectively. Piemontite occurs as small, reddish-black, monoclinic crystals in the manganese mines at San Marcel, near Ivrea in Piedmont, and in crystalline schists at several places in Japan. The purple color of the Egyptian porfido rosso antico is due to the presence of this mineral. Sample of dollaseite (dark brown matrix at arrow points) from SwedenAllanite and dollaseite-(Ce) have the same general epidote formula and contain metals of the cerium group. In external appearance allanite differs widely from epidote, being black or dark brown in color, pitchy in lustre, and opaque in the mass; further, there is little or no cleavage, and well-developed crystals are rare. The crystallographic and optical characters are similar to those of epidote; the pleochroism is strong with reddish-, yellowish-, and greenish-brown colors. Although not a common mineral, allanite is of fairly wide distribution as a primary accessory constituent of many crystalline rocks, gneiss, granite, syenite, rhyolite, andesite, and others. It was first found in the granite of east Greenland and described by Thomas Allan in 1808, after whom the species was named. Allanite is a mineral readily altered by hydration, becoming optically isotropic and amorphous: for this reason several varieties have been distinguished, and many different names applied. Orthite was the name given by Jöns Berzelius in 1818 to a hydrated form found as slender prismatic crystals, sometimes a foot in length, at Finbo, near Falun in Sweden. Dollaseite is less common, famous from the Ostanmossa mine in the Norberg district of Sweden.

Price: 9.59 USD

Location: Tucson, Arizona

End Time: 2024-12-17T05:21:39.000Z

Shipping Cost: 5.95 USD