RARE AJOITE QUARTZ Crystal Cluster Mineral Specimen MESINA MINE SOUTH AFRICA

Description: This specimen weighs 0.32 grams. It measures 17 mm x 4 mm x 3 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 incredibly rare ajoite in quartz specimen! This specimen is from Messina Copper Mine in South Africa. 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! Ajoite From Wikipedia, the free encyclopediaAjoiteAjoite-Quartz-tmu47f.jpgBluish ajoite inclusion in a colourless quartz crystalGeneralCategorySilicate mineralFormula(repeating unit)(Na,K)Cu7AlSi9O24(OH)6·3H2OIMA symbolAj[1]Strunz classification9.EA.70 (10 ed)8/D.07-10 (8 ed)Dana classification78.05.01.011Crystal systemTriclinicCrystal classPinacoidal (1)(same H-M symbol)Space groupP1Unit cella = 13.63, b = 14.5c = 13.62 [Å]; α = 107.16°β = 105.45°, γ = 110.57°; Z = 1IdentificationColorBluish greenCrystal habitSprays of bladed prismatic crystalsCleavagePerfect on {010}Mohs scale hardness3+1⁄2[2]LusterVitreousStreakGreenish whiteDiaphaneityTranslucentSpecific gravity2.96Optical propertiesBiaxial (+)Refractive indexnα = 1.550, nβ = 1.583, nγ = 1.641Birefringenceδ = 0.091PleochroismX: very light bluish green; Y and Z: brilliant bluish green2V angleMeasured: 68° to 80°SolubilityDecomposed by acidsReferences[3][4][5][6]Ajoite is a hydrated sodium potassium copper aluminium silicate hydroxide mineral. Ajoite has the chemical formula (Na,K)Cu7AlSi9O24(OH)6·3H2O,[6] and minor Mn, Fe and Ca are usually also present in the structure.[3] Ajoite is used as a minor ore of copper. DiscoveryIn August 1941 Harry Berman[7] of Harvard University was collecting at Ajo, in Pima County, Arizona, USA. He found specimens of dark blue shattuckite, together with a bluish green mineral which he suspected was a new species. Berman and W T Schaller had planned to collaborate on the investigation of this mineral, together with other known copper silicate minerals, but Berman died in a plane crash in 1944, aged 42, before this study was done. It was not until 1958 that Schaller, together with Angelina Vlisidis (both of the US Geological Survey) studied the greenish mineral and determined that it was indeed a new species. They named it "ajoite" (pronounced ah-hoe-ite) after the place where it had been found.[8] Twenty three years later, in 1981, George Chao from Carleton University in Ottawa, Canada, studied the mineral again, and showed that ajoite was triclinic, and not monoclinic as had been thought previously. His studies also resulted in a re-definition of the chemical formula.[9] Crystal structureThe 1981 investigations of ajoite were done on a sample from the New Cornelia Mine, Ajo, with tiny crystals averaging 0.01×0.1×0.4 mm. The mineral was shown to belong to the triclinic system, but it was not clear whether the crystal class was 1 or 1. The triclinic class 1 has the lowest possible symmetry with no symmetry elements at all, and 1 has just a centre of symmetry, but no axes of symmetry or mirror planes. The space group is either P1 or P1.[9] The unit cell parameters are: a = 13.637 Å, b = 14.507 Å, c = 13.620 Å, α = 107.16°, β = 105.45° and γ = 110.57°.[9] Ajoite occurs as sprays of bladed prismatic crystals, commonly fibrous, elongated along the c crystal axis and flattened sideways.[8] The dominant form is {010}, parallel to the plane containing the a and c axes. The forms {110}, cutting both the a and b axes, and {100}, parallel to the plane containing the b and c axes, are much less prominent but are always present. The termination on c may be either {001} or {203} or both.[9] Ajoite is frequently found as inclusions in quartz, much sought after by mineral collectors. Optical propertiesAjoite is translucent and bluish green in color, with a pale greenish white streak and a vitreous luster. The optical class is biaxial (+) with refractive indices Nx = 1.550, Ny = 1.583 and Nz = 1.641. These values are similar to the refractive index of ordinary window glass, at 1.5.[9] In white light the mineral is distinctly pleochroic, being very light bluish green along the X direction and brilliant bluish green along the Y and Z directions.[9] Physical propertiesThe cleavage is perfect parallel to the plane containing the a and c axes,[9] and the hardness is 3.5,[2] between that of calcite and fluorite. It is a little denser than quartz, with specific gravity 2.96.[8] Ajoite is readily decomposed by hydrochloric acid, HCl, and by nitric acid, HNO3, but it does not react with ammonium hydroxide, NH4OH. It has been reported as having barely detectable radioactivity.[5] EnvironmentAjoite is a secondary mineral that forms from the oxidation of other secondary copper minerals in copper-rich base metal deposits in massive fracture coatings, in vein fillings, and in vugs. It may form from shattuckite and also it may be replaced by shattuckite.[3] At the type locality it is associated with shattuckite, conichalcite, quartz, muscovite and pyrite.[4][6] Occurrence Ajoite in quartz from Messina District, South Africa (size: 16.9 x 3.7 x 3 cm.)Ajoite is named after its type locality, the New Cornelia Mine in the Ajo District of Pima County, Arizona. Type material is conserved at the National Museum of Natural History, Washington DC, USA, reference number 113220. Other localities include Wickenburg and Maricopa County in Arizona, within the United States, and the Messina (Musina) District in South Africa. Quartz specimens from the defunct Messina Mines on the border between Zimbabwe and South Africa are well known for their inclusions of blue copper silicate minerals such as shattuckite, papagoite and ajoite,[10] but ajoite from American localities does not occur like this.

Price: 139.99 USD

Location: Tucson, Arizona

End Time: 2024-11-12T20:32:24.000Z

Shipping Cost: 8.95 USD