Very small greenish yellow crystal group of the very rare mineral freedite from the famous Tsumeb mine in an specimen. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Freedite
Freedite is an IMA-recognized mineral species in the halide class, with the chemical formula Cu¹⁺Pb₈(As³⁺O₃)₂O₃Cl₅.
It crystallizes in the monoclinic crystal system (space group C2/m).
Key properties: Mohs hardness 3; specific gravity 7; Yellow streak; Greasy to vitreous luster; optically biaxial.
IMA symbol Fre, IMA status: approved, named in 1984.
Occurs as an uncommon mineral in andradite–magnetite ore from a metamorphosed Fe–Mn orebody.
It is found associated with Ecdemite, lead, copper, finnemanite, calcite, andradite, magnetite.
The mineral was named to honor Dr. Robert L. Freed, American mineralogist, of Trinity University, San Antonio, Texas, USA.