Mining Terminology

Here you will learn about mining terminology. For those who haven’t been around mining their whole life, listening to seasoned miners may feel like listening to a foreign language. You miss many of the key points. This list will help those who are new to mining with the basic terminology.

Common Mining Terminology

Mine TerminologyAdit – A horizontal access point to a mine.

Assay – To assay is to examine and evaluate an ore to determine the amount and type of precious metals in the ore.
Assay Office – A assay office is a professional organization whose primary purpose is to examines ores to discover their composition and then provide the results to the miner or mining company.

Assay Value – The amount of gold or silver in an ore determined by ounces per ton of ore or per assay ton.

Claim – A mining claim is the claim of the right to extract minerals from a tract of public land. A mining claim is a tangible asset. It can be sold, traded or used as collateral. It is an asset recognized by the State and Federal governments. Not all public land is available to be claimed, but much of it is.

Collar – The collar of a mine is found at the entrance of a shaft or adit.  The collar is typically made out of concrete or wood, and its purpose is to protect the entrance from erosion and caving.

Cropping – A cropping is the part of the ore deposit that is exposed and can be seen without digging.

Crosscut – A  drift that connects two tunnels. Often a crosscut is made because the miners are following an ore vein.

Drift –  All horizontal tunnels made in a mine have the generic name of drift. These are simply tunnels made in the rock that typically follow the ore vein.

Dump – Dump refers to the pile of ore or waste rock at a mine. The dump will generally be located close to the adit entry or shaft. Today most people use the word tailings to refer to both the dump and tailings pile.

Face – The end of the mine; the rock wall that you hit at the end of an Adit or shaft.

Glory Hole – A stoped out section that reaches up to the surface, allowing sunlight into the mine.

Grubstake – A grubstake is the investment material, provisions, or money supplied to a miner in return for a share in the profits.

Head Frame – Also known as a winding tower, poppet head or pit head. The Head Frame sits on top of the mine shaft and provides stability. The head frame also facilitate the extraction of ores. A hoist will usually sit atop the head frame.

Hoist – The hoist pulls the ore up out of the mine. The hoist typically consist of a motor or a sheave wheel (with the hoist motor mounted on the ground).

Incline – An inclined tunnel that is too step to be called an adit and not steep enough to be called a shaft.

Level – Larger mines with shafts often have multiple levels. These levels are cut into the rock to allow easier access to stopes or to make it easier for the miners to extract the minerals, or even to provide ventilation in the mine.

Lode –  A lode is a deposit of ore embedded in rock.

Mill – The mill is the building where the milling takes place.

Milling – Milling refers to the crushing of ore so that the precious metals can be separated from the main ore body. 

Mining Claim – A mining claim is claim on public land that allows the owner of the claim to extract and keep the minerals he or she finds.  A mining claim is a tangible asset. It can be sold, traded or used as collateral. It is an asset recognized by the State and Federal governments.

Mining District – Mines in the Western United States are assigned to mining districts depending among other factors, the location and the minerals found in the mine. The mining district were a way to regulate mines in a given area, but presently districts are mostly used for historic purposes.

Mining Engineer – an engineer that is involved with the construction and operation of mines.

Mucker – In the old days this referred to the person who’s job it was to remove the ore and host rock after it had been blasted. Today, the term mucker has a broader definition. It still refers to the individual who comes to scoop up the rock after a blast, but it also refers to the machine used to scoop up the ore and host rock.

Muck Plate – In the old days miners would place a metal sheet down in front of the section of the tunnel that they wanted to blast. This made it easier for the muckers to come and scoop up the rock after blasting.

Ore body – A deposit of minerals that contains a mixture of precious metals, including: gold, silver, copper, iron, nickle, titanium or other precious metals. Ore bodies varies in composition and thus value. Ore must be processed to extract the precious metals.

Portal – The portal is the entrance to a mine in a rock face.

Primary deposit – Primary deposits are known as lode ore where gold is originally deposited.

Prospecting – Prospecting is looking for evidence of gold. In placer mining prospecting consists of testing different areas of the placer mine to find the best area to work.  In lode mining prospectors look for geological formations, outcroppings or exposed minerals to look for the primary deposit, or the lode mine. Miners will also prospect stream beds following the gold to the source.

Raise – A raise is a tunnel that heads upwards. A raise is different than a stope, in that it is a smaller tunnel.

Secondary deposit – Secondary deposits are deposits of gold that have eroded from the primary deposit. These deposits are typically found in streams, rivers small creeks, and old river beds.

Shaft – A vertical or near vertical access point into a mine.

Shoot – An ore vein that shoots off from the main ore body vertically up or down.

Sinking – Sinking refers to the process of creating a shaft.

Skip – The cage that takes miners down into shafts.

Spine – The spine of a mine is the ceiling of the mine.

Stope – An open void in the mine where ore has been mined out.

Strike – Noun – The general direction or course of a mineral deposit. Verb – to strike refers to the act of finding an ore body, ie. striking it rich.

Sump – The sump is a low spot in the mine that receives drainage.

Tailings – Back in the day the tailings pile refered to uniformly fine sand-like material that was rejected from the mill or concentration and would generally be located below the mill building or cyanide tanks. Today the term tailings refers to all of the discarded rock, processed or otherwise. This usage of the word tailings has been standardized by the EPA and MSHA. This has also been standardized by DNR in Alaska, Arizona and Wyoming for reclamation purposes.

Tunnel – Any artificial underground passage.

Vein – A vein typically refers to an ore body that is usually smaller than the main ore body and typically narrower.

Winze – An inclined or vertical passage that connects two levels in a mine. In other words, an underground shaft that allows miners to connect to a lower level through the use of an underground hoist.

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