occurs in small proportions in creamy- grey color and is isotropic with no internal reflection.
These prismatic, well terminated crystals, some associated with sharp black cubic bixbyite
crystals, are hardly "new," having been first discovered in 1859 (according to a 1979 article by Lanny Ream: see vol.
We hypothesize that a correlation exists between the crystallization of quartz and bixbyite
2] was found to lose oxygen at about 600 [degrees]C and 950 [degrees]C to bixbyite
The mineral bixbyite
, which he discovered there, was named in his honor by Penfield and Foote in 1897.
In addition to topaz, the most common vapor phase minerals include quartz, garnet, hematite, pseudobrookite, bixbyite
, red beryl, and fluorite; many of which are uncommon in silicic volcanic rocks.
Since that time both areas have yielded an ongoing bonanza of beautiful crystals of topaz and beryl as well as other minerals including bixbyite
and rare species such as durangite.
It occurs as a pneumatolitic phase in cavities and fractures in a rhyolite, together with hematite, bixbyite
, fluorite, topaz and red beryl.
Other, less common mineral species that have been reported from the Klein Spitzkoppe occurrences include bixbyite
, chabazite, columbite, euxenite-(Y), gibbsite, nacrite, opal (hyalite), pyrophyllite, talc, ferberite and zircon.
6 Black Pine Mine, Phillipsburg (MT), Bixbyite
(AZ), Platinum-Palladium (Brazil), Franklinphilite [square] v.
Utah Minerals and Fossils had a nice exhibit of topaz and associated bixbyite
from the Thomas Range, Utah.
Last year at the Wessels mine, bixbyite
in bright black (though rough-faced) cubes to 1 cm were found, in groups with clear, colorless calcite rhombs, some of which make very nice thumbnails.