Emily Dickinson Lexicon

SEL'EN-ITE, n. [Gr. σεληνιτης, from σεληνη, the moon; so called on account of its reflecting the moon's light with brilliancy.]

1. Foliated or crystalized sulphate of lime. Selenite is a subspecies of sulphate of lime, of two varieties, massive and acicular. – Cleaveland. Kirwan. Nicholson.
2. A compound of selenous acid with a base.