When available, a silicious rock containing copper or the precious metals is of course preferred to barren lining.
Those which I saw appeared to belong to that species of the silicious genus usually called Gneiss, a sort of slaty granite.
These consisted chiefly of quartz, felspar, and a silicious petrifaction of woody appearance.
The surface rock is hard, silicious limestone with bands of flint.
Subsequently another company was formed in New York, being influenced by a fallacious view of the silicious sand.
The white powder is for the most part an impure, silicious, kaolin.
The purest springs are those which occur in primitive rocks, or beds of gravel, or filter through sand or silicious strata.
The staple of the soil ought to be silicious, fertile, and deep.
We followed the sea-shore, which is composed of silicious sand, and covered with a carpet of creeping shore plants in full bloom.
Diatoms in a fossilised condition are silicious, and they are to be found in Virginia, in Bermuda, and here.