Turquoise
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Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl648·4H2O. It is rare and valuable in finer grades and has been prized a
Turquoise 40031
"Big Blue", a large turquoise specimen from the copper mine at Cananea, Sonora, Mexico
Massive Kingman blue turquoise in matrix with quartz from the Mineral Park mine, Arizona, US
Turquoise of Madan-e Olya of Nishapur
Robin egg blue
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Robin egg blue, also called eggshell blue or robin's-egg blue, is a shade of cyan, approximating the shade of the eggs laid by the American robin, an abundant songbird of North America. The egg pigmen
Turquoise
…the chemical formula CuAl6(PO4)4(OH)8·4H2O. It is rare and valuable in finer grades and has been prized as a gemstone for millennia due to its hue. The robin egg blue or sky blue color of the Persian turquoise mined near the modern city of Nishapur, Iran, has been used as a guiding reference for evaluating turquoise…
American robin eggs