A gorgeous specimen of amethyst in oriented overgrowth over a calcite crystal. This oriented overgrowth creates “stripes” down the centre of each calcite face. Because some specimens of this kind of overgrowth have black goethite among their stripes, they gained the name “skunks”, and the term has been more generally used for specimens exhibiting this phenomenon. The exact reason for oriented overgrowths down the centre line of calcite faces has been explored but not definitively explained. The individual amethyst crystals are in various orientations relative to the underlying calcite crystal, so this is not epitaxy (all crystals would be oriented in the same way if it was an epitactic growth). Amethyst “skunks” are always highly sought-after.
In excellent condition, minor chips. This specimen from the John White quartz collection was figured in Rocks & Minerals v. 88:4, p. 369, along with Rock Currier’s famous skunk amethyst specimens. A killer!