The Mineral melanophlogite
Melanophlogite is a rare form of silica, and is in a unique class in that it contains organic compounds in its chemical structure. This technically excludes it from being classified as a mineral, since one of the definitions of a mineral is that it is an inorganic substance. Despite this, the acclaimed Dana's System of Mineralogy categorizes Melanophlogite and a few other rare organic 'minerals' together with the true minerals, being that it is naturally formed and irrelevant of biological interference.
In a few deposits, such as the Case Montanini Quarry in Italy, the Melanophlogite has been pseudomorphed into Quartz or Opal.
Chemical Formula
46(SiO)2
· 6(N2,CO2) · 2(CH4,N2)
Color
Colorless, white, yellow, brown
Crystal System
Tetragonal
Properties
Streak
White |
Hardness
6.5 - 7 |
Transparency
Transparent to translucent |
Specific Gravity
2.0 |
Luster
Vitreous |
Cleavage
None |
Fracture
Conchoidal |
Tenacity
Brittle |
Uses
Melanophlogite is only used as a rare collectors mineral.
Noteworthy Localities
Melanophlogite is a rare mineral. The most important localities are in Italy, where it occurs in Fortullino, Livorno Province, as clear rounded blobs and balls; and in the Case Montanini Quarry in Pedasano, Parma Province, as cubic-shaped crystals. Melnophlogite also comes from Italian island of Sicily in the Giona Mine, Milena (Caltanissetta Province); and in Racalmuto, Agrigento (Girgenti). It is found in the U.S. on Mount Hamilton in the Diablo Range, Santa Clara County, California.
Common Mineral Associations
Sulfur, Calcite, Celestine, Barite, Opal
Distingushing Similar Minerals
The localities and mode of occurrence are enough to distinguish this rare mineral from all other minerals.