Melanophlogite - Encyclopedia

    Class : Silicates
    Subclass : Tectosilicates
    Crystal system : Tetragonal
    Chemistry : SiO2 n(C, H, O, S)
    Rarity : Very rare

Melanophlogite is a particular silicate in which the voids available between the SiO4 tetrahedra are occupied by organic compounds and sometimes sulfur, essential for the stability of the crystalline structure. Its name comes from the Greek melanos (black) and phlogai (to burn) because some samples of this mineral drown when burned. Crystals are rare (usually millimeter-size pseudocubes). Melanophlogite generally occurs in rounded polycrystalline aggregates with complex shapes, evoking drops, and building fine encrustations. Organic compounds are present in varying amounts (7 to 12%). Melanophlogite is colorless when pure, but often pale yellow to dark red-brown, due to the presence of impurities. It is a rare mineral, little known to collectors, which has no particular use.

Melanophlogite in the World

It is a very rare low temperature mineral crystallizing in the sulfur deposits of Sicily (Racalmuto and Caltanissetta, where it forms on sulphur crystals), and in carbonate serpentines (Mount Hamilton in California and Fortullino in Italy). It is also known in a rhodochrosite and pyrite hydrothermal vein intersecting the Chvaletice manganese deposit in the Czech Republic.

Melanophlogite in France

The best melanophlogite crystals come from France and more particularly from the Limagne Basin in Puy-de-Dôme. They can form individual centimeter-sized pseudocubes and stacked groups of several centimeters. It is systematically found associated with lussatite, chalcedony and bitumen on the Mine des Rois deposit in Dallet.


No twin known for this mineral species.

Fakes and scams

No fake recorded for this mineral species.

Hardness : 6.5 to 7
Density : 2
Fracture : Conchoidal
Trace : White

TP : Translucent to transparent
IR : 1.425 to 1.457
Biréfringence : Very low
Optical character : Uniaxial +
Pleochroism : None
Fluorescence : White

Solubility : Hydrofluoric acid

Magnetism : None
Radioactivity : None