Tridymite w/ Osumilite (rare) Ordway Coll.

Item Description

Tridymite is high-temperature quartz and osumilite is a rare comple silicate, both found in volcanic rocks. Tan tridymite crystals (rare at this well-known Sardinian locale) richly line a vug in rhyolite matrix and a rich band and isolated crystals of brown, lustrous, hexagonal, prisms and blades, to 3 mm, of osumilite are a fine compliment to this rare and showy combination specimen. Ex Al Ordway Collection and obtained in a trade in 1985.