from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Gypsum in the form of colorless clear crystals.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A soft, glassy form of gypsum (chemical formula CaSO4·2H2O).
- n. The anion SeO32− derived from selenous acid; any salt or ester of selenous acid.
from the GNU version of the Collaborative International Dictionary of English
- n. A salt of selenious acid.
- n. A variety of gypsum, occuring in transparent crystals or crystalline masses.
from The Century Dictionary and Cyclopedia
- n. [capitalized] A supposed inhabitant of the moon.
- n. A foliated or crystallized and transparent variety of gypsum, often obtained in large thin plates somewhat resembling mica; also, specifically, a thin plate of this mineral used with the polarizing apparatus of the microscope.
- n. In chem., a salt of selenium.
There is a mineral called selenite which is also named after the word selene; however, selenite does not contain selenium.
With this view, I will take a representative crystal, one easily dealt with, because it cleaves with great facility -- the crystal gypsum, or selenite, which is crystallized sulphate of lime.
This gypsum was still in solution, but was later precipitated out of solution as these astonishing selenite (hydrated calcium sulfate) crystals when the water containing it seeped into caverns.
The monster crystals, over six meters long, are made of selenite, a crystalline form of the mineral gypsum (the number one ingredient in blackboard chalk!).
In two relatively small chambers, each the size of a small apartment, miners found incredibly large selenite crystals, some over six meters long.
The first is that the selenite crystals began to grow in pre-existing steam-filled caverns as a direct result of the same hydrothermal fluids that formed the ore deposits.
For its pale translucence, this form of gypsum is known as selenite, named after Selene, the Greek goddess of the moon.
Several typical examples of selenite crystals from this cave, ranging in length from 1.2 to 1.6 meters (4 to 4.25 feet), are displayed in the Smithsonian's National Museum of Natural History.
Ten years later, super-large sword-shaped crystals of selenite were found in a cavern at a depth of 120 meters.
Held during meditation, selenite crystals are said to enhance sex drive and fertility and relieve stress.