Hedyphane - Encyclopedia
Class : Phosphates, arsenates, vanadates
Subclass : Anhydrous arsenates
Crystal system : Hexagonal
Chemistry : Pb3Ca2(AsO4)3Cl
Rarity : Rare
Hedyphane is a chlorinated lead and calcium arsenate belonging to the apatite group. It is a rare secondary mineral from various hydrothermal deposits of varying lead content: metamorphic manganese deposits (Langban and Harstig in Sweden), stratiform zinc deposits (Franklin, New Jersey), polymetallic deposits (Tsumeb, Namibia). Its name comes from the Greek hedus (pleasant, luminous) and phainein (to appear) to highlight its adamantine luster. Hedyphane forms thick prismatic or tabular crystals, usually bipyramidal, or colorless masses, white or pale yellow, sometimes pale blue, purplish or light brown.
Main photo : Hedyphane from Beltana Mine, Puttapa, Australia © John Toma
Hedyphane in the World
Twinning
No twins known for this mineral species.
Fakes and treatments
No fakes recorded for this mineral species.
Hardness : 4 to 5
Density : 5.82
Fracture : Sub-conchoidal
Streak : White
TP : Translucent to transparent
RI : 1.948 to 2.030
Birefringence : 0.010
Optical character : Uniaxial (+/-)
Pleochroism : None
Fluorescence : Pale orange
Solubility : Nitric acid
Magnetism : NoneRadioactivity : None