When I lived in Bisbee in the 1970's, I would go into the mines and often found the post mine Cu color in places and one time found a soda straw of multicolored Cu salts that was over a foot long.  Knowing the chalcanthite in the Bisbee mines was not stable, I left the straw there.   I had been given a foot long stalactite of chalcanthite by a miner who lived next door.   It was sadly not stable and I enclosed it in a jar but it kept altering.  I  only wish I had taken a camera and taken photos when I went underground.

This POTD is great!!

It has already in the management team been discussed what to call it. But we are probably within langite-posnjackite series.