The situation now is that I don't currently have any shoes that I'd feel good walking around all day long in...not the way we like to walk. I have good running shoes, but I really don't feel like wearing those on a trip to Europe. This is asking way early - but if it takes me a few tries to find the right shoes, I'd rather get that sorted out sooner, rather than later.
Selenite is a variety of the mineral gypsum, which has a chemical formula of calcium sulfate dihydrate.The dihydrate part of that formula indicates that each unit has two molecules of water attached to it.elenite is a variety of the mineral gypsum, which has a chemical formula of calcium sulfate dihydrate.
Gypsum and Halite: Evaporite Minerals Gypsum is readily identified by its softness (a fingernail scratches it). Gypsum comes as clear crystals that display one perfect cleavage (selenite), as blocks of featureless white rock (alabaster), and as silky fibrous blocks (satin spar).Halite (next page) breaks into cubes (three cleavages at right angles) and tastes like table salt. Go to Halite page.lear crystals or crystal fragments of gypsum are called selenite. These are four more cleavage fragments of selenite. The good cleavage is again parallel to the ground surface. There are also two poor cleavages that can be seen in three of the four samples shown here.