Oooooook , i'll have to say that i love rocks !!and my friends laugh about that :) . I love natural materials in general , but rocks have their magic for me . I wanted to be a geologist and coulden't but i studied geology after all ;) and i'm thankful for that. Of course the most PERFECT rock is diamond -and that's another story - but here i'll let some of them know about Gypsum , LOL .
Gypsum is a soft mineral, hydrous calcium sulfate. Gypsum is the standard for hardness degree 2 on the Mohs mineral hardness scale. Your fingernail will scratch this mineral—that's the simplest way to identify gypsum.It may be glassy with obvious cleavage, granular, or have a fibrous, satiny luster. It ranges from colorless to white to pink. The clear variety that makes up the wedge in the first picture is called selenite after the pearly luster of its cleavage faces, likened to moonlight.
Gypsum also forms concretions of selenite blades called desert roses or sand roses, growing in sediments that are subjected to concentrated brines. The crystals grow from a central point, and the roses emerge when the matrix weathers away. They don't last long at the surface, just a few years, unless someone collects them - second and third picture- .Most gypsum occurs not in crystals but in massive chalky beds of gypsum rock .
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