Anorthite (Feldspar) (classic locality)

Item Description

Here we have a fine quality thumbnail sized example of these classic, yet notably hard to find Anorthite crystals from this little island locale about 180 km (110 miles) south of Tokyo. For reference Anorthite is the calcium-rich end member of the Albite-Anorthite Feldspar series, and the label accompaning this piece states that it is, "remarkably close to the end-member composition. This old-time thumbnail specimen features a predominant, sharp Anorthite crystal that is mostly coated by reddish-brown oxidation on the surface. Miyake Island is a small island with an active volcano and is famous as the classic locality for Anorthite crystals, thousands of which were thrown out loose by the 1870 eruption and distributed in collections around the world (according to the entry on mindat.org). There are tiny nicks, exposing the Anorthite underneath the oxidized coating. From the worldwide collection of David Burgess (1951-2016) with a label from noted Japanese mineral expert, Alfredo Petrov. David was a prolific species collector from Newington, Connecticut, and the namesake for the extremely rare cobalt arsenate species Burgessite, which he discovered.