Tewite

tewite

wumuite

monazite-(Ce)

tellurite

Images

Formula: (K1.50.5)Σ2(Te1.25W0.250.5)Σ2W5O19
Composite oxide, tellurium- and tungsten- bearing mineral
Crystal System: Orthorhombic
Specific gravity: 6.903 calculated
Hardness: 3½ to 4
Streak: Light yellow to white
Colour: Greenish yellow
Environments

Plutonic igneous environments
Hydrothermal environments

Tewite was approved in 2014, but to date (July 2022) it has been reported only from the type locality.

Localities

At the type locality, Nanyang, Huaping County, Lijiang, Yunnan, China, tewite occurs in biotitequartz monzonite, near the contact zone with gabbro. The associated minerals include K-feldspar, biotite, clinoamphibole, ilmenite, zircon, zoisite, tourmaline, monazite-(Ce), allanite-(Ce), scheelite, tellurite and wumuite. Tewite forms platy greenish-yellow crystals that range up to 0.5 mm in size.
The formation of tewite may be related to the nearby quartz-vein-type gold mineralisation; it is formed by the metasomatic reaction of a high-temperature fluid rich in tungsten and tellurium with the K-feldspar in the monzonite (EJM 31.1.145–152).

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