Desert Rose Mexico 1 Piece Raw Minerals Crystals Stones Rocks Collecting (5)

Desert Rose Mexico 1 Piece 26.5 gr - mm 37 x 35 x 33 Raw Minerals Stones Rocks for Collection Gypsum Crystals, only a piece, as in photo.

The Desert Rose is a common sedimentary formation in desert countries. With a color that fades from orange to yellow-ocher, it is an aggregate of Gypsum crystals that forms in well-defined environmental and climatic conditions.
The gypsum that composes the desert roses crystallizes in the monoclinic system in lens-shaped aggregates in thinner flat crystals at the ends.
The mineral has sedimentary genesis. For it to form, at least two fundamental conditions are needed: the presence of a chalky evaporite deposit and an arid climate. In the evaporite deposit located in the subsoil at a certain depth comes groundwater (ie gushing or filtering from the subsoil) or rainwater that dissolve the calcium sulphate. The resulting solution tends to gradually rise towards the surface due to the principle of capillarity and, having reached a certain depth close to the surface, the water begins to evaporate, making the gypsum crystallize. Subsequent ascents and continuous evaporations allow the growth of crystals up to decimetric dimensions.
The most famous deposits are those of the Sahara among which are noteworthy: El Oued and Touggourg in Algeria and Zuara in Libya, other relevant locations are in Tunisia, Morocco. Desert roses can also be found in the US deserts of New Mexico and Arizona. Shapes similar to desert roses can be found in the clays of the Emilian Apennines including in Castel de 'Britti in the metropolitan city of Bologna.
Desert nomads are the main researchers and collectors of desert roses, which they sell to tourists for a small profit. In the most favorable situations, the roses are found directly emerging on the surface, freed from the sands by the wind, and if they are not collected immediately after their natural burial, the rains bring the plaster into solution, flaking the crystal. Conversely, if the crystal aggregates are still buried under a few meters of sand, they are identified by probing the subsoil with metal probes. Once the deposit has been identified, the collector digs a tunnel until it reaches the mineral in order to be able to extract it with the crystals still intact.