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Melanophlogite with Sulfur

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)
Composition Silicon dioxide with organic compounds
Variable Formula SiO2 • n(N,C,O,H,S)
Color Colorless, white, yellow, brown
Streak White
Hardness 6.5 - 7
Crystal System Tetragonal
3D Crystal Atlas
(Click for animated model) 
Crystal Forms
and Aggregates
Occurs in pseudo-isometric crystals, possibly from the transformation of Beta Cristobalite. Crystals occur as small cubes, often rounded in shape, appearing as small balls or blobs. Also in botryoidal, reniform, encrusting, or in coxcomb balls. Crystals and aggregates are always small.
Transparency Transparent to translucent
Specific Gravity 2.0
Luster Vitreous
Cleavage None
Fracture Conchoidal
Tenacity Brittle
In Group Silicates; Tectosilicates; Silica Group
Striking Features Occurrence, crystal shape, association with Sulfur
Environment In low-temperature Sulfur deposits and altered Serpentine deposits.
Rock Type Sedimentary, Metamorphic
Popularity (1-4) 4
Prevalence (1-3) 3
Demand (1-3) 3

Melanophlogite AUCTIONS

Melanophlogite is only used as a rare collectors mineral.

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.

Sulfur, Calcite, Celestine, Barite, Opal

The localities and mode of occurrence are enough to distinguish this rare mineral from all other minerals.

melanophlogite PHOTOS
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