Flattened blades of Heubnerite forming loose divergent groups in quartz.
A spray of Heubnerite crystals.
A mass of crystalline Heubnerite
showing its reddish brown color.
CHEMISTRY MnWO4 Manganese tungsten oxide
CRYSTALLOGRAPHY Monoclinic
CRYSTAL GROWTH AND HABITS Heubnerite is commonly prismatic to long prismatic, less commonly short prismatic or tabular. Crystals are often found in groups of sub parallel sprays or divergent groups.
COLOR AND OTHER OPTICAL PROPERTIES Reddish brown; translucent
HARDNESS 4 - 4.5
SPECIFIC GRAVITY 7.1
LUSTER Vitreous to sub metallic
STREAK Reddish brown
BREAKABILITY Heubnerite has one very good cleavage.
OCCURRENCE Heubnerite is found in high temperature hydrothermal veins.
ASSOCIATED MINERALS Cassiterite, Tourmaline, Topaz, Scheelite, Hematite, Quartz