Minerals Quotes (1 quote)
We maintain that there are two exhalations, one vaporous the other smoky, and these correspond to two kinds of bodies that originate in the earth, things quarried and things mined. The heat of the dry exhalation is the cause of all things quarried. Such are the kinds of stones that cannot be melted, and realgar, and ochre, and ruddle, and sulphur, and the other things of that kind, most things quarried being either coloured lye or, like cinnabar, a stone compounded of it. The vaporous exhalation is the cause of all things minedthings which are either fusible or malleable such as iron, copper, gold.