Locality: A quarry at the Bellerberg volcano lava field, near Ettringen, 2 km north of Mayen, Laacher See region, eastern Eifel area, Germany.

Occurrence: In xenoliths in leucite tephrite lava. Associated minerals are: tridymite, sanidine, a clinopyroxene, an amphibole, quartz, hematite and braunite.

General appearance: Euhedral crystals, thick tabular on {001}; maximum diameter 1.5 mm and 0.2 mm thick.

Physical, chemical and crystallographic properties: Luster: vitreous. Diaphaneity: presumably transparent to translucent. Color: yellow to orange. Streak: light orange. Luminescence: nonfluorescent. Hardness: not given. Tenacity: brittle. Cleavage: none. Fracture...

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