تۉزیVolga Blue Granite (anorthosite) Zhitomir Province, Ukraine.jpg
Volga Blue Anorthosite - a dark, very coarsely-crystalline anorthosite with zoned plagioclase feldspar from Ukraine. This is from the Volodarsk-Volhynsky Intrusion in the southern Korosten Complex, a large igneous suite intruded through the Ukrainian Shield. The Volodarsk-Volynsky Intrusion dates to the late Paleoproterozoic (1.758-1.760 Ga). This material is quarried between the cities of Korosten and Zhitomir, central Zhitomir Province, northwestern Ukraine.
Anorthosites are uncommon intrusive igneous rocks almost exclusively composed of Ca-rich plagioclase feldspar. There’s usually a blackish pyroxene component as well. Anorthosites having labradorite plagioclase feldspar will display a wonderfully colorful iridescent play of colors (labradorescence). This makes them desirable decorative stones.