Gypsum
Strkovice deposit, Strkovice, Postoloprty, Louny District, Ústí nad Labem Region, Czech Republic
8.26 carats
© irocks.com
Gypsum is a very common mineral in sedimentary environments. It is found as massive material (Alabaster), clear crystals (Selenite) and parallel fibrous variety (Satin spar).
Gypsum is very soft and very difficult to facet because of its perfect cleavage, therefore faceted stones are quite rare.
Gypsum Gemstones by Colour
This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
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Gypsum Gemstones by Size
This table shows distribution of Gypsum gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:1.90 cts
Heaviest:8.26 cts
Average:5.08 cts
Total photos:2
Do you have a larger Gypsum? Why not upload a photo?
| General Information | ||||||||||||||||||||||||||||||
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| Varieties/Types: | Alabaster - A fine-grained massive form of Gypsum. Satin Spar - A fibrous variety of Gypsum. Selenite - Transparent, colourless variety of Gypsum. | |||||||||||||||||||||||||||||
| Chemical Formula |
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| Physical Properties of Gypsum | ||||||||||||||||||||||||||||||
| Mohs Hardness | 2, Gemstones of the world (2001) More from other references | |||||||||||||||||||||||||||||
| Specific Gravity | 2.20 to 2.40, Gemstones of the world (2001) More from other references | |||||||||||||||||||||||||||||
| Cleavage Quality | Perfect, Gemmological Tables (2004) More from other references | |||||||||||||||||||||||||||||
| Fracture | Uneven, Gemstones (2009) | |||||||||||||||||||||||||||||
| Heat Sensitivity | Very sensitive, Gemstones of the world (2001) | |||||||||||||||||||||||||||||
| Optical Properties of Gypsum | ||||||||||||||||||||||||||||||
| Refractive Index | 1.521 to 1.531, Gemmological Tables (2004) More from other references | |||||||||||||||||||||||||||||
| Optical Character | Biaxial/+, Gemmological Tables (2004) More from other references | |||||||||||||||||||||||||||||
| Birefringence | 0.010, Gemmological Tables (2004) More from other references | |||||||||||||||||||||||||||||
| Pleochroism | Nil, Gemstones (2009) | |||||||||||||||||||||||||||||
| Dispersion | Nil, Gemstones (2009) | |||||||||||||||||||||||||||||
| Chatoyancy | Yes, Gemmological Tables (2004) | |||||||||||||||||||||||||||||
| Colour | ||||||||||||||||||||||||||||||
| Colour (General) | White, yellowish, colourless, pink, bluish., Gemstones of the world (2001) More from other references | |||||||||||||||||||||||||||||
| Transparency | Transparent,Translucent,Opaque, Gemstones of the world (2001) More from other references | |||||||||||||||||||||||||||||
| Lustre | Vitreous,Silky, Gemstones of the world (2001) Fibrous aggregates have silky lustreMore from other references | |||||||||||||||||||||||||||||
| Crystallography of Gypsum | ||||||||||||||||||||||||||||||
| Crystal System | Monoclinic, Gemstones of the world (2001) More from other references | |||||||||||||||||||||||||||||
| Habit | Tabular, Gemstones (2009) | |||||||||||||||||||||||||||||
| Further Information | ||||||||||||||||||||||||||||||
| Mineral information: | Gypsum information at mindat.org | |||||||||||||||||||||||||||||
| Significant Gem Localities | ||||||||||||||||||||||||||||||
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