Hydroxylapatite with Hornblende (ex Kay Robertson Collection)

Item Description

Please note that this piece came labled as Apatite with Tourmaline, but I'm certain based upon information I've found that it's actually Hydroxylapatite with Hornblende. This piece features a prismatic hexagonal crystal of ash-white Hydroxylapatite (possibly a pseudomorph after another species) which is associated with prismatic greenish-black Hornblende on the back. The piece is easily over 100 years old. Ex Kay Robertson Collection (#5633). Kay is a prominent California collector, who specialized in European classics (see the article in the March-April, 2007 Mineralogical Record and the 50+ page article in the German Magazine "Mineralien Velt" November-December 2017).