FAULT: A dislocation along a crack in the earth’s surface (may be horizontal, vertical or a combination of both); a failure along a line of stress; usually associated with earthquakes, but movement may be slow.
FISSURE: a crack in the earth’s surface; if filled with vein material becomes a fissure vein.
FLOAT: a piece of ore detached from a vein or lode, lying loose, not in place.
FLOOR: the lower surface of a mine working, i.e. the floor of a drift.
FLUME: a device for conveying water.
FOOT WALL: the lower side of an inclined vein in country rock.
GANGUE: the matrix of the ore composed of worthless material.
GLORY HOLE: a large funnel-shaped excavation extending to the surface, the material being drawn from the bottom through a tunnel.
GRIZZLY: a grating, usually made up of mine rails, over an ore bin for the purpose of diverting large rocks or boulders.
GRUB STAKE: financing a prospector to share in his findings.