If you are requesting a locality be added, please only include significant locality occurences for the mineral. About Minerals. Link Directory Donations Mobile Site. Chemical Formula. Hydrous calcium sulfate. Colorless, white, gray, brown, beige, orange, pink, yellow, light red, green. Crystal System. Crystal Forms and Aggregates. Commonly as tabular crystals, sometimes perfect with no imperfections.
Also prismatic , acicular , bladed , and as dense bundles of fragile acicular crystals. Other forms are as fibrous vein s, scaly , grainy , lenticular , rosette , massive , and as parallel, cactus-like growths. Crystals and fibrous masses may be curved, sometimes severely, forming formations that are sometimes called "Rams Horns". Crystals frequently twin , forming perfect fishtail twin s or swallowtail twin s. Crystals can be enormous in size. In fact, the largest crystals ever found on earth were of Gypsum.
Transparent to opaque. Specific Gravity. Vitreous to pearly. Sectile and slightly flexible. Other ID Marks. Often fluorescent light yellow in shortwave ultraviolet light , and occasionally also phosphorescent. In Group. Sulfates ; Hydrous Sulfates. Striking Features.
Crystal habits, low hardness , flexibility , and sectility. In enormous deposits and beds in sedimentary rock , specifically limestone. Also in clay sedimentary deposits, and in dry cave s. Occasionally in igneous traprock and in the oxidation zone of sulfide deposits. Rock Type. Igneous , Sedimentary. Popularity Prevalence Demand Alabaster - Massive, fine grained variety of Gypsum. Desert Rose - Rosette shaped Barite or rosette shaped Gypsum with sand inclusion s.
Gypsum Flower - Rosette shaped Gypsum found in caverns with spreading fiber s. The group reported that gypsum actually forms in a three-step process: precipitation of nanocrystals of bassanite — or calcium sulfate hemihydrate, with one water molecule for every two calcium sulfate units — followed by the assembly of those crystals into larger aggregates, and finally transformation of the aggregates into gypsum.
In prior research on gypsum, scientists had utilized X-ray diffraction and electron diffraction to investigate dry, powdered samples of the gypsum precursors. For the study, however, the team, led by Tomasz Stawski of the GFZ German Research Centre for Geosciences, used X-rays generated by a synchrotron particle accelerator to study samples of the gypsum precursors calcium chloride and sodium sulfate mixed in aqueous solution, thus more closely approximating the conditions in which the mineral forms in nature.
Witnessing these building blocks led Stawski, van Driessche and their colleagues to identify a four-stage development of gypsum, updating the earlier three-stage process.
In the first stage, noncrystalline bits of calcium sulfate called primary species, which are less than 3 nanometers in length, begin to form.
Finally, in stage four, the aggregates grow and crystallize into gypsum. This new research also provided an explanation for a previous study, which found that altering the presence and concentration of water and ethanol can determine whether the end result turns out as gypsum, bassanite, a third form of calcium sulfate called anhydrite — which is fully dehydrated — or a combination of the three. It is especially used in constructing materials such as drywall, however it is also useful in agriculture as soil fertilizer and conditioner.
Gypsum is fire resistant in nature which prevent the possibility of fire outbreaks that ensure life safety. The heating of gypsum products causes water crystals to form within the material; this dehydration by heat is known as calcination. The casing results on combustion-tolerant materials and allows low safe temperatures to be maintained. Even after the water crystals have cooled completely, the residue behaves like an insulating layer until it separates.
It is considered an excellent fire retardant due to its non-combustible property and may delay fire spread for hours. Other methods such as masonry work commonly used in higher thicknesses; plasterboard is specifically designed to prevent noise reduction and redistribution. The air space between the two solid wall results in excessive acoustic efficiency which prevents noise from being passed. Instead of a mm thickness masonry wall , we are able to install 75 mm thickness drywall to achieve the same sound efficiency.
The thermal properties are capable of creating very good stability of indoor humidity and temperature. Gypsum construction such as plasterboard or formwork construction has additional insulation properties. It is used as a plaster material, if given properly whiteness which is free from scars. It is environmentally friendly, fire-resistant in nature, extreme thermal and acoustic insulation.
Using these products inside the wall construction, we simply want to repair the frame and fill the joints.
The entire process is simple and quick; using this plaster as the final finish minimizes additional painting work. The uses include architecture, art, ceramics, food essences, pharmaceutical and medical plasterboard and various uses are as follows:.
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