Calcite

ncat TI Descloizite, Calcite, Grey Horse Mine, Riverside, Riverside Mining District, Dripping Spring Mountains, Pinal Co., Arizona, USA

Colourless calcite crystals that fluoresce pale pink under shortwave UV, with dark brown descloizite crystals. An interesting specimen. There appears to be multiple generations of calcite. The “Mercedes” faces are obviously a later addition, and there is zoning apparent in the fluorescence. White light photo: Width of view 6mm, stack...

ncat JP2-24-2 A2127 Cuprite, Connellite, Brochantite, Marshite, Smithsonite, Calcite, Block 14 Opencut, Broken Hill, Broken Hill district, Yancowinna Co., New South Wales

An aesthetic and really interesting specimen. Four well-formed cuprite crystals with tiny green brochantite crystals and blue connellite puffballs, sitting on a bed of white smithsonite stained by goethite. Then under longwave UV, you can see a couple of light red fluorescing calcite crystals, and small areas of tiny marshite...

5754 Biraite-(Ce), Hydroxylbastnasite-(Ce), Strontianite, Aragonite, Calcite, Cordylite-(Ce), Cordylite-(La), Niobochevkinite-(Ce), Ferriallanite-(Ce), Talc, Thorite, Daqingshanite-(Ce), Daqingshanite-(La), Ancylite-(Ce), Ancylite-(La), Kukharenkoite-(Ce), Carbocernaite, Cordilitovaya carbonatite vein, Ust’-Biraya deposit, Vitim Plateau, Eastern Siberia, Russia

Extremely rich 8x7x2mm specimen containing abundant inclusions (red arrowed) of brown biraite-(Ce) – an extremely rare silico-carbonate of REE. Biraite contains microscopic inclusions of hydroxylbastnasite-(Ce) and intergrows with its more yellow macro grains well recognisable under magnification (yellow arrowed). Light matrix of the sample represented by pale-greenish, apatite-like strontianite-aragonite with...

5384 Calcite, Chenzhou, Hunan Province, China

Yellow calcite with bluish-white fluorescence (Convoy) and a green afterglow that takes a few seconds to fade. Colours are not exact in photo (iPhone). Also, compared to the many many calcite specimens from Chenzhou in Mindat, this is atypical. There is a large variety of forms, but not like this...