Mining Terminology A

• Acidic rocks: Igneous rock that has a higher amount of silica.
• Acidic precipitation: Consists of rain and snow that have a low pH, originated by sulphur dioxide and nitric oxide gases from industrial doings that has been set free into the atmosphere.
• Acid mine drainage: Acidic run-off water from mill tailings ponds and mine waste dumps that have sulphide minerals.
• Adit: A hole that is made horizontally into the side of a mountain or hill in order to provide access to a mineral deposit.
• Aerial magnetometer: A device that is used to measure the strength of a magnetic field from an airplane.
• Aeromagnetic survey: A geophysical survey that is done with a magnetometer that is usually aboard or towed behind.
• Agglomerate: A breccia mainly consisting of or entirely of fragments of volcanic rocks.
• Agglomeration: Technique of concentrating precious minerals depending on their adhesion properties.
• Agitation: Stirring of shaking that is done in metallurgy by a mechanical means and sometimes done by introducing compressed air.
• Airborne survey: A survey that is done from an aeroplane in order to get photographs, or measure magnetic properties, radioactivity and so forth.
• Alloy: A composite of two or more metals.
• Alluvium: Recent deposits of sedimentary material that can be found in lakes, river beds, flood plains, or at the bottom of mountain slopes.
• Alpha meter: A tool utilized to measure positively charged particles released by radioactive materials.
• Alteration: A physical or chemical alteration in a rock or mineral following its formation.
• Amorphous: A word that is utilized for rocks or minerals that do not have any specific crystal structure or form, like that of amorphous carbon.
• Amphibolite: A gneiss or schist that is for the most part made up of plagioclase or amphibole minerals.
• ANFO: Short form for ammonium nitrate and fuel oil which is a mixture utilized as a blasting agent in a lot of mines.
• Anode: A rectangular plate of metal cast in a shape suitable for refining by the electrolytic process.
• Anomaly: Any exit from the standard that might show the presence of mineralization in the underlying bedrock.
• Anthracite: Hard and black coal that has a high percentage of fixed carbon and a small amount of volatile matter.
• Anticline A fold that can be seen in layers of rock that have the shape of the crest of a wave.
• Apex: The top border of a vein on surface or its closest point to the surface.
• Ash: Non-organic residue that is left after coal has been ignited. 
• Assay: A chemical test that is done on a sample of ores or minerals to establish the quantity of precious or valuable materials are in it.
• Assay foot: The assay worth multiplied by the number of feet, metres, inches, and so forth across which the sample is done.
• Assay map: The view of an area that shows the values of the essays and the locations of the samples that were done on the land or property.
• Assessment job: The quantity of work, specified by mining law, that needs to be done every year so as to be able hold on to the legal control of mining claims.
• Autogenous grinding: A process in which the ore is ground in a cyclinder that rotates with the using of big pieces of ore rather than the usual steel balls or rods that are used.