Find the word definition

Wiktionary
admontite

n. (context mineral English) A soft mineral composed of magnesium, boron, oxygen, and hydrogen.

Wikipedia
Admontite

Admontite is a hydrated magnesium borate mineral with formula MgBO·7HO.

Occurrence - In a gypsum deposit. Associations: gypsum, anhydrite, hexahydrite, löweite, eugsterite, pyrite, quartz.

It is named after Admont, Austria. Its Mohs scale rating is 2 to 3.