Pencil Selenite

Pencil Selenite (or Pencil Gypsum) is long narrow crystals of gypsum found only in the old gypsum mine in Grand Rapids, Michigan.

Selenite, is a variety of the mineral gypsum.

All varieties of gypsum, including selenite and alabaster, are composed of calcium sulfate dihydrate (meaning has two molecules of water), with the chemical formula CaSO4·2H2O. Selenite contains no significant selenium; the similarity of names comes from both substances being named from the Ancient Greek word for the Moon.

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