As glassy and gemmy as fluorite gets, this gorgeous crystal is from a famous small pocket found at the Gibraltar Mine in 1985. The crystal is twinned – it has been described as a spinel-law twin, but it’s actually a penetration twin. This fluorite crystal is so sharp and lustrous and it is transparent, with blue and purple colour zones. There are fluid inclusions with moving bubbles, visible with a loupe.
The photos against the darker background show the crystal forms better, and the photos against the white background show the colour most accurately.
In excellent condition, no damage (incomplete on the underside where it was attached to the matrix). From the Tracy Kimmel collection, acquired from The Arkenstone. It is on mindat.org with the MinID# 08T-HPD, and it was the Mindat Photo of the Day on May 2, 2009. An absolute killer!