Turquoise / Nishapur / large pendant / cabochon / new- 11.44 g - (1)

Pendant Nishapur Turquoise / Cabochon / new Set in 925 sterling silver Includes leather strap Weight: 11.44 g !!! (weighed without leather strap) 23.9 mm x 19.3 mm x 11.1 mm New and unworn The turquoise mineral is a rare hydrated copper-aluminum phosphate from the mineral class of the “Phosphates, Arsenates and Vanadates” with the chemical composition CuAl6(PO4)4(OH)8·4H2O. In place of aluminum, iron as Fe3+ can be incorporated into the crystal structure (diadochy), hence the chemical formula is also often given as Cu(Al,Fe)6(PO4)4(OH)8·4H2O. Turquoise crystallizes in the triclinic crystal system and is the eponym of a group of minerals with the same structure but different composition, the turquoise group, with the other members faustite, chalkosiderite, aheylite and planerite. In nature turquoise typically forms in cluster-like or earthy-mass mineral aggregates. Crystals visible to the naked eye are very rare and then only a few millimeters in size with a prismatic to needle-like habit. Its characteristic blue‑green color is the source of turquoise’s name. Turquoise is exclusively processed as a gemstone for jewelry. Shipping as insured registered mail

Estimate:£127.23

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