DENVER SHOW 2015: COBALT MINERALS

Photomicrograph of pink crystals from specimen below.  Width ~7 mm.

Although I sort of hobbled around the displays at the recent Denver Show (see posting September 21, 2015), I was able to visit a few dealers and make several small purchases.  I am always looking for some special minerals, especially those with nice crystal form and color.  Therefore, I was excited to see some specimens collected from Bou Azer, Ouarzazate Province, Morocco.  A recent post (July 13, 2015) described several cobalt minerals that are a bright pink in color.  The minerals I purchased ($5 or less per specimen) include: roselite [Ca₂(Co,Mg)(AsO₄)₂-2H₂O], cobaltoan calcite [(Ca,Co)CO] and erythrite [Co₃(AsO₄)₂-8H₂O].  Although I had these minerals in my collection, the newly purchased ones are larger and “nicer.”  All are idiochromatic minerals whereby cobalt, with its distinctive coloration, is included within the crystal lattices.

Colbaltoan calcite crystals width ~4 cm.  Camera would not pick up the vibrant pink color.

Another specimen of cobaltoan calcite.  FOV ~1.3 cm.

Nice crystals of fibrous erythrite from specimen below.  Width of crystals 1 cm.

Fibrous erythrite scattered across specimen. Width ~7cm.

Streak of roselite crystals.  Width ~4.5 cm.

Photomicrograph roselite crystals from specimen above.  Width ~ 1 cm.

 It ain't over till its over.  So long Yogi, I guess your earthly stay is over.  You were my hero.  RIP 1925-1915.

1953 "baseball card."  public domain.