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Glossary of Terminology: Metals & Metallurgy Terms


Glossary of Metallurgy Terms

Metallurgy & Metal-Working Terminology & Definitions
  • Alchemy (a) Alchemy was the science (or pseudo-science) of combined disciplines in chemistry, metallurgy, physics, and mysticism with the goal of transforming base metals into precious metals.
  • Alloy (n) A combination of two or more elements, at least one of which is a metal, and where the resulting material has metallic properties. 14 carat (58%) gold is an alloy of pure gold (24k) mixed with other elements.
  • Alluvial Gold (a) Gold that is found in the soil or sediments deposited by a river, stream, or other running water. (aka Placer of Surface Gold).
  • Annealing (v) Multi-phased heat and stress treatment that alters the microstructure of a metal adding strength, pliability, and hardness.
  • Adamantine (a) Refers to the light reflecting properties of a metallic surface, known as metallic lustre.
  • Base Metal (a, n) Base metal is a term used to refer to a metal that oxidizes or corrodes relatively easily as with copper, iron, nickel, lead and zinc.
  • Carat (n) The term "Carat", "Karat" or "k" is used to indicate the amount of pure (24k) gold in the alloy. Lower Carat ratings indicate proportionally less pure gold.
  • Carbon (n) Carbon is a chemical element in the periodic table (C) and atomic number 6. An abundant nonmetallic, tetravalent element, carbon has several allotropic forms including Diamond. Carbon occurs in all organic life and is the most basic element in organic chemistry.
  • Corrosion (n) Corrosion indicates the deterioration of a metallic material due to its reaction and subsequent oxidation due to a chemical reaction with water and/or oxygen.
  • Diamagnetism (n) The property of an object which causes it to create a magnetic field in opposition of an externally applied magnetic field, thus causing a repulsive effect.
  • Ductile, Ductility (v) A physical quality ascribed to a metal that will permit plastic elongation (wire drawing) without fracturing.
  • Firescale (n) Also known as "firestain," a red or purple discoloration that appears at high temperatures when oxygen mixes with the copper to form cuprous oxide, and then cupric oxide.
  • Forging (Forged) (v) Heating a metal to a temperature where the metal becomes malleable (red hot) or deforming its shape by compression or exertion of force (hammering or cold forging).
  • Goldsmith (n) A goldsmith is a metalworker who specializes in working with precious metals to create jewelry.
  • Hydrous (a) A hydrous compound is formed by the addition of water to a host molecule. In inorganic chemistry, hydrates contain water molecules that are either bound to a metal center or crystallize with the metal complex.
  • Ingot (n) An ingot is a mass of metal heated past its melting point and then cast into the shape of a bar or block.
  • Lustre (n) From the Latin word "lux", meaning "light". Describes the way light interacts with the surface of a mineral or metal.
  • Malleable, Malleability (v) A physical quality ascribed to a metal that can be compressed, deformed, extruded, hammered, and rolled.
  • Mineralization (n) In Metellurgy, mineralization is used to describe the hydrothermal (heat and water vapor) deposition of metals in the formation of ore.
  • Mohs scale (a, n) Created, in 1812, by the German mineralogist Friedrich Mohs, the Mohs' scale of hardness quantifies the scratch resistance of minerals by comparing the ability of a harder material to scratch a softer material ranging from Talc (1) to Diamond (10).
  • Noble metal (a, n) Noble metals are highly resistant to corrosion or oxidation and include gold, silver, platinum, tantalum, and rhodium.
  • Ore (n) An ore is a volume of rock containing components or minerals which renders it valuable for mining. Rare samples of metallic ore are found in large nuggets or chrystaline formations of metals such as gold or copper.
  • Oxidation (v) Oxidation removes electrons from a metal, and is thus reduces its mass. Oxidation (Redox) reactions include all chemical processes in which atoms have their oxidation number (oxidation state) changed.
  • Oxidation State (v) An indicator of the degree of oxidation of an atom in a chemical compound. Oxidation states are represented by integers, which can be positive, negative, or zero.
  • Periodic Table (n) The periodic table of chemical elements is a tabular method used to classify, systematize and compare all the 116 (94 natural, 22 synthetic) basic chemical elements.
  • Placer Gold (n) Surface gold found in sand or gravel or "free metallic" "stream placer gold." Named after the Spanish word placer meaning "sand bank", or "alluvial deposit."
  • Plastic, Plasticity (v) A physical quality ascribed to a metal that can be bent and worked without rupturing. A non-brittle metal.
  • Magnetic Ordering (n) Describes the overall magnetic behavior of a material as: Diamagnetism, Paramagnetism, Ferromagnetism, and Superparamagnetism.
  • Metamorphic Rock (n) Metamorphic rock make up a large part of the Earth's crust. They are formed deep beneath the Earth's surface under great stress from high pressures and temperatures.
  • Reef Gold (n) Gold found through "hard rock mining", reef gold is synonymous with the terms ledge, lode, and vein. Reef gold is solid masses of gold that is imbedded into a matrix of a wide variety of other rocks and minerals.
  • Smelting (v) smelting, is a form of extractive metallurgy used to produce a metal from its basic ore components.
  • Thermal Conductivity (a, n) The property of a material which indicates its ability to conduct heat. It appears primarily in Fourier's Law for heat conduction.
  • Vickers Hardness (n) The Vickers Hardness test is used to quantifying a materials' ability to resist plastic deformation when force is applied from a standard source. Result is known as "Vickers Pyramid Number" or (HV).

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