Anorthoclase
Lake Kizaki
Taira, Omachi city, Nagano pref., Japan
Synonym
Moonstone
Field of view: 3 mm. Anorthoclase phenocryst. The bluish-white grain at the center is anorthoclase. The translucent gray grains are beta-quartz, the tabular opaque white crystals are K-feldspar.
Recovered from Kizaki Rhyolite. Formed in Late Cretaceous.
The first anorthoclase from Japan was reported from this location in 1927.