Gault. A bluish clay underlying the Chalk and Upper green sand in England.
Gavial. A species of shark found in the Ganges.
Geodes (in mineralogy) a round hollow stone whose cavity is usually filled with crystals.
Glacis. A gently sloping bank.
Glyptolepis. (Gr., carved scale.)
Glyptopomus. A Devonian fossil fish.
Gneiss. The name given to mixtures of quartz, feldspar, and mica, in which there is a laminated arrangement of the different ingredients.
Goniatites. Chambered fossil shells.
Granite. A rock consisting generally of crystals of feldspar and mica imbedded in a quartzy base.
Graminæ. Grasses.