Other precious stones, including the sapphire, emerald, oriental emerald, ruby, opal, amethyst, garnet, chrysolite, topaz, cairngorm, onyx, zircon, etc., have been found in the gold and tin bearing drifts and river gravels in numerous localities throughout the states.
All these are wanting in the Pacific area, though there are indications in its gold-bearing gravels that it once possessed them.
The earlier wells in Pennsylvania consisted of three sections, the first formed of surface clays and gravels, the second of stratified rocks containing water, and the third of stratified rocks, including the oil-sands, usually free from water.
They have also been found in Pleistocene gravels in several parts of England, as Maidenhead, Bromley, Freshfield near Bath, Barnwood near Gloucester, and in the brick-earth of the Thames valley at Crayford, Kent; while their remains also occur in Arctic America.
The somewhat imperfect skull of an extinct species of musk-ox from the gravels of the Klondike has enabled Mr W.