Sparkly Zincite Gem 6.1ct

This is a zincite crystal that I faceted.  It weighs in at 6.1ct.

These crystals grew unintentionally in a Polish zinc refinery smokestack which was demolished in the 70s.  It is also filled with sparkly zinc crystals.  These unfortunately also cause unavoidable scratching in the final polish but they also add a rainbow sheen when viewed from the right angle.  The stone also has some minor chipping.