(twin) on celestine, Sicily, Italy, no.
A new locality for melanophlogite
, in small, colorless, cubic crystals to about 0.
Melanophlogite is a clathrate polymorph of silica stabilized by molecules of gases such as [N.
Some brown-white color-banded chalcedony has been found in the upper workings, as well as green botryoids with cinnabar inclusions which may be pseudomorphs after melanophlogite.
Melanophlogite does occur at Clear Creek, a mineral that requires some sort of stabilizing molecules such as C[O.
2002) Pseudomorphic melanophlogites from California.
Melanophlogite, the tetragonal pseudocubic polymorph of Si[O.
Although melanophlogite is considered to have a cubic structure, studies of material from two localities (Chvaletice, E.
Skinner and Appleman (1963) gave an extensive historical account of melanophlogite research from 1876 through 1891.
Zak (1967, 1972) has studied the crystal chemistry of melanophlogite from Chvaletice (E.
Identical optical effects were observed in melanophlogite from Sicily by Bertrand (1880), Friedel (1890) and Skinner and Appleman (1963).
The Mount Hamilton locality is about 23 km north of Orestimba Creek and has produced, in addition to chromian alumohydrocalcite, the finest examples of melanophlogite
crystals ever found (Cooper and Dunning, 1972).