Merry Meet...gather around our fire side...
It should once be put right, that the crystals from the known Crystal Mountain (28° 26′ E and 27° 39′ N) between the oasis Bahariya and Farafra, northern of the White Desert,
are no Quartz crystals. They are probably Barite (Schwerspat, BaSO4) and/or Calcite crystals (Kalkspat, CaCO3), which to ascertain at the hardness of the crystals easily.
Quartz (SiO2) has the hardness 7, Barite and Calcite the hardness 3.5-3.0 (Mohs-scale).
Quartz crystal can scratch glass, Barite or Calcite can it not.
The origin of this Crystal Mountain is interesting. The hill was opened during works at the road from Farafra to Bahariya by chance and destroyed in part.
The material was installed into the road. Today is the Crystal Mountain
a popular stop for the tourists.
Still more interesting is thegeological context. The hill is not a paleokarst cave
with columnar-shaped stalagmites. It is a subvolcanic vault,
which was emerged probably during the Oligocene age.
The visible layers are e.g. White Desert limestone of the Khoman Fm.
* (Late Cretaceous age), as well as a younger coal seam and hydrothermal impregnated
reddish to brownish ferruginous layers.
The strata are broken or brecciated and intensely with each other folded.
It is to be ascertained intense heat.
The coal seam e.g. was transformed to anthracite (?).
The crystals have increased out of climbed hydrovolcanic solutions.
The hot solutions were high concentrated with BaSO4 and/or CaCO3,
which had been solved from the sediments.
The solutions have penetrated into all cavities.
After cooling of the solutions the crystals could increase.
It were formed columns or round domes with crystals within.
* The white limestone of the Khoman Formation is dated
as middle to latest middle Maastrichtian
(Gansserina gansseri and Contusotruncana contusa foraminiferal Zones).
An open marine, warm Tethyan outer shelf environment of deposition is inferred.
“High grade Barite mineralization is found mainly in the form of different veins restricted to the ground surface of Bahariya depression.
The barite veins trend in different directions and are actually associated with the major folds and faults that are restricted to the
oldest rocks of Sabaya Formation which form the floor of the depression.
The latter occurs within a major northeast trending belt of considerable
extension about 100 km long and 40 km wide.
Several other folds of the same or later tectonic phase but of lesser extension occur parallel to or
perpendicular to the main anticlinal trend.
The Barite veins are widely distributed to the south of Gebel El Hafhuf
which is composed of a rock sequence including sandstone, shale, limestone,
phosphatic limestone and phosphatic calcareous sandstone.
This succession is capped by the Oligo-Miocene basaltic sheet which takes the form
of open circle of about 20 m thickness.
The barite veins are restricted to the fractures that are parallel to the main E-W or NW-SE striking faults in the Sabaya Formation.
These veins occur subparallel sets with more
than 7 m length and ranging in width between 0.5 to 4 m.
These veins are numerous and distributed in
association with tectonically formed fractures and fissures.
Barium was leached from the basaltic extrusion during high temperature circulation.
Tertiary Oligocene basalt at Gebel El Hafhuf, Bahariya Oasis
is related to continental intraplate volcanism. Fumarolic and geyser
activities belong to Oligocene period
were consider as gas maar resulting from a phreatic explosion.
Release of sulphate fluids from the sulphate-rich minerals involved in the Brine deposits distributed within Bahariya Depression at the Quaternary,
namely polyhalite, kieserite and kyanite.
by barite mineralization as a result of a rapid primary precipitation at or above the sediment / fluid interfaces.
The white desert in Egypt is very different to the rest of the surrounding desert terrain in the Western Desert.alf way between Bahariya oasis and Farafra oasis lies crystal mountain, some call it crystal desert, because of the abundance of crystals found in the area. The rocks in the photos below are all of rock formations and contain crystals. This is evidence of a large cave system that used to exist in this areas hundreds of thousands of years ago which today has become Crystal mountain.
The “Crystal Mountain” in Egypt
A subvolcanic vault, filled with crystals of a hydrothermal event