Jouravskite with QuartzThis lovely lemony yellow crust on a bed of transparent and iron coated quart

Jouravskite with QuartzThis lovely lemony yellow crust on a bed of transparent and iron coated quartz crystals is a rare calcium manganese sulphate mineral. It was only named in 1965 after the chief geologist of the Moroccan Geological Survey, where it was first discovered. Colour varies from green through orange to yellow, and its extreme softeness (2.5 on Mohs scale) means that specimens should be treated with great care due to their delicate nature.It forms in oxidised zones of polymetallic metal deposits rich in manganese, where oxidised groundwaters percolating through the ore body have turned the primary reduced minerals into secondary ones (see http://bit.ly/1I4XWKt for an explanation of the process). This 4.1 x 3.7 x 3.0 cm specimen was mined at N'Chwanning in Souther Africa’s Kalahari Manganese Field.LozImage credit: Rob Lavinsky/iRocks.com http://www.mindat.org/min-2118.html http://bit.ly/28O3XBj http://bit.ly/28QBhwc -- source link

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