Rare KYANITE Specimen Gemmy Crystal Cluster ALMANDINE GARNET Mineral RUSSIA

Description: This specimen weighs 10.48 grams. It measures 32 mm x 27 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 amazing Kyanite with Almandine Garnet crystal specimen from Khit Ostrov, North Karelia, Russia. It is a beautiful translucent blue. I have never seen such translucent kyanite until I came across these specimens from North Karelia. There's really nothing else like them. 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! KyaniteFrom Wikipedia, the free encyclopediaKyaniteKyanite crystals.jpgGeneralCategory NesosilicateFormula(repeating unit)Al2SiO5Strunz classification 9.AF.15Crystal systemTriclinicCrystal classPinacoidal (1)(same H-M symbol)Space groupP1Unit cella = 7.1262(12) Åb = 7.852(10) Åc = 5.5724(10) Åα = 89.99(2)°, β = 101.11(2)°γ = 106.03(1)°; Z = 4IdentificationColorBlue, white, rarely green, gray, yellow, pink, orange, and black, can be zonedCrystal habitColumnar; fibrous; bladedTwinningLamellar on {100}Cleavage[100] perfect [010] imperfect with 79° angle betweenFractureSplinteryTenacityBrittleMohs scale hardness4.5-5 parallel to one axis6.5-7 perpendicular to that axisLusterVitreous to pearlyStreakWhiteDiaphaneityTransparent to translucentSpecific gravity 3.53 - 3.65 measured; 3.67 calculatedOptical propertiesBiaxial (-)Refractive indexnα = 1.712 - 1.718 nβ = 1.720 - 1.725 nγ = 1.727 - 1.734PleochroismTrichroic, colorless to pale blue to blue2V angle78°-83°References[1][2][3]Kyanite is a typically blue silicate mineral, commonly found in aluminium-rich metamorphic pegmatites and/or sedimentary rock. Kyanite in metamorphic rocks generally indicates pressures higher than four kilobars. Although potentially stable at lower pressure and low temperature, the activity of water is usually high enough under such conditions that it is replaced by hydrous aluminosilicates such as muscovite, pyrophyllite, or kaolinite. Kyanite is also known as disthene, rhaeticite and cyanite. Kyanite is a member of the aluminosilicate series, which also includes the polymorph andalusite and the polymorph sillimanite. Kyanite is strongly anisotropic, in that its hardness varies depending on its crystallographic direction. In kyanite, this anisotropism can be considered an identifying characteristic. At temperatures above 1100 °C kyanite decomposes into mullite and vitreous silica via the following reaction: 3(Al2O3·SiO2) → 3Al2O3·2SiO2 + SiO2. This transformation results in an expansion.[4] Its name comes from the same origin as that of the color cyan, being derived from the Ancient Greek word κύανος. This is generally rendered into English as kyanos or kuanos and means "dark blue". Contents [hide] 1Uses2Notes for identification3Occurrence4References5 External linksUses[edit]Kyanite is used primarily in refractory and ceramic products, including porcelain plumbing fixtures and dishware. It is also used in electronics, electrical insulators and abrasives. Kyanite has been used as a semiprecious gemstone, which may display cat's eye chatoyancy, though this use is limited by its anisotropism and perfect cleavage. Color varieties include recently discovered orange kyanite from Tanzania.[citation needed] The orange color is due to inclusion of small amounts of manganese (Mn3+) in the structure.[5] Kyanite is one of the index minerals that are used to estimate the temperature, depth, and pressure at which a rock undergoes metamorphism. Notes for identification[edit] Deep blue kyaniteKyanite's elongated, columnar crystals are usually a good first indication of the mineral, as well as its color (when the specimen is blue). Associated minerals are useful as well, especially the presence of the polymorphs of staurolite, which occur frequently with kyanite. However, the most useful characteristic in identifying kyanite is its anisotropism. If one suspects a specimen to be kyanite, verifying that it has two distinctly different hardness on perpendicular axes is a key to identification; it has a hardness of 5.5 parallel to {001} and 7 parallel to {100}.[1][2] Occurrence[edit]Kyanite occurs in gneiss, schist, pegmatite, and quartz veins resulting from high pressure regional metamorphism of principally pelitic rocks.[citation needed] It occurs as detrital grains in sedimentary rocks.[citation needed] It occurs associated with staurolite, andalusite, sillimanite, talc, hornblende, gedrite, mullite and corundum.[1] Kyanite occurs in Manhattan schist, formed under extreme pressure as a result of the two landmasses that formed supercontinent Pangaea.[6]

Price: 19.99 USD

Location: Tucson, Arizona

End Time: 2024-09-09T04:47:42.000Z

Shipping Cost: 5.95 USD