Adverb
According to the principles of, or with reference to, mineralogy.
Source: Webster's dictionaryMindat.org Presently, the word "fluorspar" is most commonly used for fluorite as the industrial and chemical commodity, while "fluorite" is used mineralogically and in most other senses. Source: Internet
Silt is mineralogically like sand but with its higher specific surface area it is more chemically active than sand. Source: Internet