Raw Selenite Mineral - AAA-Grade
A chunky, highly translucent piece of the mineral selenite.
Selenite is a variety of gypsum. Gypsum is a soft mineral composed of calcium sulphate dihydrate. Dihydrate means it contains two molecules of water.
When dissolved in water, calcium sulphate causes permanent hardness because it doesn't precipitate easily.
Gypsum is widely used as a fertiliser, for blackboard chalk, and is the main constituent of plaster (and plaster of Paris). Selenite is crystallised gypsum.
Satin spar and selenite are not the same, although they're often confused. Satin spar has long, fibrous crystals that are white and opaque, with a silky or pearly lustre. It's often incorrectly labelled as selenite.
Selenite forms colourless, translucent or transparent crystals and is so soft that it can be scratched with a fingernail.
Although it can't be appreciated from our photos, this piece has a vitreous lustre. Minerals with this kind of lustre reflect light in a similar way to glass.
Selenite should never be submerged in water because it will cause irreparable damage. For protection, consider keeping a silica gel sachet nearby to absorb moisture in the air.
