DANBURITE Crystal Mineral Specimen Natural Terminated Point GEMSTONE MEXICO for Sale

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DANBURITE Crystal Mineral Specimen Natural Terminated Point GEMSTONE MEXICO For Sale

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DANBURITE Crystal Mineral Specimen Natural Terminated Point GEMSTONE MEXICO:
$5.59

This specimen weighs 0.60 grams. It measures 14 mm x 5 mm x 4 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!
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Onceall of your items are in your cart just pay for them from your cart andthe 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 beautiful danburite crystal mineral specimen! This specimen comes from Aurora Mine near Charcas, San Luis Potosi, Mexico. If you have any questions, do not hesitate to ask me. Have fun offerding, thanks so much for visiting my store and have a great history
ToolsFrom Wikipedia, the free encyclopediaDanburite
Cluster of creamy crystals of danburiteGeneralCategory TectosilicatesFormula(repeating unit) CaB2(SiO4)2IMA symbol Dbu[1]Strunz classification 9.FA.65Dana classification 56.3.1.1Crystal system OrthorhombicCrystal class Dipyramidal (mmm)H-M symbol: (2/m 2/m 2/m)Space group PnamUnit cell a = 8.038(3), b = 8.752(5)c = 7.73 [Å]; Z = 4IdentificationColour Colourless, white, gray, brownish white, straw yellowCrystal habit Euhedral prismatic crystals; disseminated massesCleavage {001} PoorFracture Subconchoidal to unevenTenacity BrittleMohs scale hardness 7 – 7.5Lustre Vitreous to greasyStreak WhiteDiaphaneity Transparent to translucentSpecific gravity 2.93 – 3.02Optical properties Biaxial (+/-)Refractive index nα = 1.627 – 1.633 nβ = 1.630 – 1.636 nγ = 1.633 – 1.639Birefringence δ = 0.0062V angle 88 to 90° measuredDispersion r < v strongUltraviolet fluorescence Fluorescent and thermoluminescent (red); Short UV=violet blue; Long UV=blue to blue-greenReferences [2][3][4]Danburite is a calcium boron silicate mineral with a chemical formula of CaB2(SiO4)2.[5]
It has a Mohs hardness of 7 to 7.5 and a specific gravity of 3.0.[5] The mineral has an orthorhombic crystal form.[5] It is usually colourless, like quartz, but can also be either pale yellow[5] or yellowish-brown. It typically occurs in contact metamorphic rocks.
The Dana classification of minerals categorizes danburite as a sorosilicate, while the Strunz classification scheme lists it as a tectosilicate;[4] its structure can be interpreted as either.
Its crystal symmetry and form are similar to topaz; however, topaz is a calcium fluorine bearing nesosilicate. The clarity, resilience, and strong dispersion of danburite make it valuable as cut stones for jewelry.
It is named for Danbury, Connecticut, United States, where it was first discovered in 1839 by Charles Upham Shephard.[5]