Housleyite
Housleyite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Pb₆CuTe₄O₁₈(OH)₂.
It crystallizes in the monoclinic crystal system (space group P2_1/n).
Key properties: Mohs hardness 3; specific gravity 7.845; Pale blue streak; Adamantine; frosted crystal faces are dull luster; optically biaxial.
IMA symbol Hou, IMA status: approved, named in 2009.
A secondary phase on fracture surfaces and in small vugs in quartz veins. Formed from the partial oxidation of primary sulfides (e.g., galena) and tellurides (e.g., hessite) during or following brecciation of the quartz veins.
It is found associated with Acanthite, cerussite, gold, hessite, iodargyrite, khinite-4O, wulfenite, thorneite, markcooperite, ottoite.
The mineral was named to honor Robert M. Housley (b. 1934), Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA.