Heinrichite - Encyclopedia
Class : Phosphates, arsenates, vanadates
Subclass : Uranyl arsenates
Crystal system : Tetragonal
Chemistry : Ba(UO2)2(AsO4)2 10H2O
Rarity : Very rare
Heinrichite is a hydrated arsenate complex of barium and uranium from the oxidation zone of uranium deposit. It is a mineral from the autunite group which derives from the alteration of uraninite (and therefore pitchblende) and accompanies other secondary arsenates, notably uranium (zeunerite, novacekite, etc...). It was named in honor of the American Eberhardt William Heinrich, Professor of Mineralogy at the University of Michigan. Heinrichite occurs in small tabular crystals with square or rectangular outlines, 2 mm at most, usually grouped in scaly aggregates, yellow to greenish yellow in color ; it fluoresces brightly in green-yellow under UV light.
Main photo : Heinrichite from Schmiedestollen dump, Wittichen, Germany © G. Franz Zöll
Heinrichite in the World
Twinning
No twins known for this mineral species.
Fakes and treatments
No fakes recorded for this mineral species.
Hardness : 2.5
Density : -
Fracture : Undeterminated
Streak : Yellow
TP : Translucent to transparent
RI : 1.573 to 1.605
Birefringence : 0.032
Optical character : Uniaxial -
Pleochroism : None
Fluorescence : Yellow-green
Solubility : -
Magnetism : NoneRadioactivity : Strong