[ Top ] [ Japanese ]

Hydrotungstite

Year of discovery: 1944 (San Antonio de Calacalani mine, Bolivia), 1981 (Japan)

Locality list: A locality of hydrotungstite

• WO₂(OH)₂,H₂O
• [W⁶⁺][(OH)₂|O₂]^6-,H₂O

• Class: Oxide - Hydroxide - Hydrate
• Very unstable. Almost all stocked specimens dehydrate to Tungstite.
• Formed by alteration of Scheelite.

• Polymorph: Meymacite (Amorphous)

• 2H₂O => 0.5H₂O: Hydrokenoelsmoreite
• 2H₂O => H₂O: Tungstite

• Color: Dark green
• Tarnish: Yellow, Lighter than Tungstite and Hydrokenoelsmoreite.
• Streak: Greenish yellow
• Luster: Vitreous

• Cleavage: Indistinct on {010} (1 plane)
• Hardness: 2
• Density: 4.6

• System: Monoclinic
• Group: 2/m, P2/m
• Lattice: a=7.5, b=6.9, c=3.7, β=90.5