Mining-Prospecting Dictionary

  * G alena: A bluish-gray to lead-gray mineral. It frequently contains included silver minerals. It has a shiny metallic luster, exhibits highly perfect cubic cleavage, and is relatively soft and very heavy. Galena is the most important ore of lead and one of the most important sources of silver.
  * Gangue: Waste rock that surrounds an ore deposit; also the valueless material in an ore.
  * Geode: A hollow nodule of agate, usually lined with crystals.
  * Geology: Science dealing with the formation of rocks, ores and minerals.
  * Geophysics: Analysis of rock formations by use of physics.
  * Glacial: Of, or related to, glacial action; produced by glaciers.
  * Glacial Deposits: A general term for debris transported by glaciers or icebergs, and deposited directly on land or in the sea
  * Glaciation: 1. The formation, movement, and recession of glaciers or ice sheets. 2. The covering of large land areas by glaciers or ice sheets. 3. The geographic distribution of glaciers and ice sheets. 4. A collective term for the geologic processes of glacial activity, including erosion and deposition, and the resulting effects of such action on the Earth's surface. 5. Any of several minor parts of geologic time during which glaciers were more extensive than at present.
  * Gold mineralized material: Mineralization based on geological evidence and assumed continuity. May or may not be supported by samples but is supported by geological, geochemical, geophysical or other data. This material is sufficiently geologically defined to be deemed to be potentially economic, yet is not in a definitive mine plan. This material requires a reasonable cut-off grade criteria and has no untenable non-technical issues barring its exploitation.
  * Gold table: Volume or weight of placer gravel or an ore.
  * Gophering: Prospecting by means of hand dug holes.
  * Gouge: Softer minerals lining the wall of a vein or ore deposit.
  * Graben: An elongated, relatively depressed crustal unit or block that is bounded by faults on its long sides.
  * Grade: The amount of valuable mineral in each ton of ore, expressed as troy ounces per ton or grams per tonne for precious metals and as a percentage for other metals.The metal content of ore. With precious metals, grade is expressed as troy ounces per ton of ore or grams per metric tonne of ore. Cut-off Grade: The lowest grade of mineralized material that qualifies as ore in a given deposit; ore of the lowest assay value that is included in an ore estimate. Mill Head Grade: The grade of ore as it comes from a mine and goes to a mill. Recovered Grade: Actual metal content of ore determined after processing. Reserve: The quantity of mineral that is calculated to lie within given boundaries. It is described as total (or gross), workable, or probable working, depending on the application of certain arbitrary limits in respect of deposit thickness, depth, quality, geological conditions, and contemporary economic factors. Proved, probable, and possible reserves are other terms used in general mining practice.
  * Gr aduated cylinder: Flask marked with lines to indicate measured volumes.
  * Grain: Unit of weight. There are 480 grains in a troy ounce.
  * Gram: Metric unit of weight. There are 31.103 grams in a troy ounce.
  * Granular: Composed of compacted mineral grains.
  * Graphitic: Containing carbon or graphite.
  * Gravity Circuit: A method by which mineral particles are separated with the aid of water or air, according to the differences in their specific gravities.
  * Gravity Separation: Recovery of gold from crushed rock or gravel using gold's high specific gravity to separate it from the lighter material.
  * Grinding: Size reduction of ore into fine particles to prepare it for processing, comminution.
  * Grizzly: Iron grating for screening out larger rocks and boulders.
  * Gulch: A narrow or deep ravine or canyon.
  * Gully: A small ravine.
  * Gumbo: Very sticky or clayey mud.
  * Gutter: The lowest depression in the bottom of a stream channel.