grey or green or brown mineral similar to mica and containing aluminum and potassium sulphates
source: WordNet 3.0
A compact granular cryptocrystalline mineral of a dull grayish or greenish white color. It is a hydrous alkaline silicate, and is derived from the alteration of other minerals, as iolite.
source: Webster 1913
Any fossil wood which exhibits traces of having belonged to the Pine family.
