Mindat.org Glossary

An ultramafic volcanic rock, dominated by olivine, phlogopite and diopside +/- garnet, commonly highly serpentinized, ...

gemmy 1: Having the characteristics (as hardness, brilliance, color) desired in a gemstone. 2: Glittering, Bright [Ref: ...

amygdaloid A vesicular or cellular igneous rock, ordinarily basaltic, in which the vesicles have been partly or completely ...

An obsolete old name for sulphides/sulfides ( see sulfuret)

Pac. The undecomposed metallic ores, usually sulfides. Chiefly applied to auriferous pyrites. An old syn. for sulfide. ...

amygdaloidal rock A rock containing amygdules and/or amygdales, or the structure of a rock resulting from its presence. [Ref: ...

amygdaloidal geode A geode which has formed in and amygdaloid. [Ref: Shipley] See amygdaloid

amygduler A lava in which the steam holes have been filled with chalcedony or other minerals. [Ref: Hess] Also see amygdaloid

amygdale A vesicle or vapor cavity of volcanic and occasionally of intrusive rocks, which has become filled (partly or ...

amygdule or amygdale A vesicle or vapor cavity of volcanic and occasionally of intrusive rocks, which has become filled (partly ...

a. Containing amygdules. Like or pertaining to an amygdaloid. [Bureau of Mines Staff.] b. ...

Cirque A deep steep-walled basin high on a mountain, usually shaped like half a bowl and often containing a small lake, caused ...

Corrie, also spelled Corry. A term used in Scotalnd for a circular hollow on the side of a hill or mountain: a cirque. See also ...

Taconite pellets are made from taconite ore (cherty or jaspery rock with a high iron content). As the iron ore of the great iron ...

A network of intersecting blades or plates of limonite or other iron oxide, deposited in cavities and along fracture planes from ...

A texture showing a porous aggregate with plates or septa which intersect at various angles leaving open boxlike ...

Hollow, bubblelike, or roselike spherulites, usually with a concentric structure, that occur in rhyolite, obsidian, and related ...

A circular rock-lined pit in which broken ore is pulverized by heavy stones attached to horizontal poles fastened in a central ...

These are pyrope garnets from Navajo Indian Reservation, McKinley Co., New Mexico, USA. Most of the garnets are quite small and ...

A general name used for consolidated rocks composed of silt and/or clay and of the associated materials which, when mixed with ...

A section of metal stock, either round or hexagonal (from an old drill steel), tapered on one end, and inserted into a short ...

A local miners' term for sphalerite in the Franklin, New Jersey, mining district zinc mines. Term alludes to the shiny cleavage ...

Kidney stone: a. A nodule of iron stone common in the Oxford clay (Middle Oolite) of England. b. A tough compact fine grained ...

Gem mining method in Burma. It is a pit which is 6 or more meters in diameter and 25-30 meters in depth. The walls are ...

Gem mining method in Burma. Today it is seldom used. It is a round pit, the walls of the pit were reinforced with logs ...

Gem mining method in Burma. A gwè-dwin (hard-rock hole) is similar to a loo (or loo-dwin - twisted holes), but instead of ...

This word is the local Burmese term denoting the type of gem-bearing gravel. Fine to medium grained, brown, yellowish ...

The term loo or loo-dwin (twisted holes) is applied to natural caves or deep fissures of the karst topography of Mogok. The ...

A type of gem mining in Burma. Found in the karst topography of Mogok. It is a fracture-filled deposit, like a small narrow ...

A mining method used for gem mining in Burma. It is a vertical pit, a little over one square meter and usually between 15-20 ...

This word is the local Burmese term denoting the gem-bearing gravel. It is a layer of gem-bearing alluvium left by solution of ...

A mining method used for gem mining in Burma. On selected hillsides, or between slopes, workers dig openings to remove the ...

Rock crystal, from Herkimer County, N.Y. Shipley Herkimer diamonds are a variety of quartz crystals from Herkimer, Co. New ...

Zebra stone is simply a commercial name for a banded brown and white sedimentary rock found in the Kimberley region of Western ...

This is a list of authorities and sources taken from the list in the back of A Dictionary of Mining, Mineral and Related Terms ...

An abbreviation for Mid Ocean Ridge Basalt. Said of basalts that form by 15 to 30 percent partial melting of the upper mantle at ...

An abbreviation for Tonalite, Trondhjemite, and Granodiorite. Found in granitic complexes and batholiths and compose most of the ...

i. A rarely used term for a chimneylike orebody. Synonym of: pipe ii. An irregular, metalliferous mass in a rock formation, ...

Within the QAPFM classification scheme proposed by the IUGS, rocks with less than 90 vol-% mafic minerals are classified by their ...

The IUGS proposed a now generally accepted scheme for classifying igneous rocks by their mineral composition (modal composition). ...

Synonym of QAPF diagram.

A classification scheme for volcanic rocks based on their bulk chemical composition. TAS stands for Total Alkali versus ...

A ternary diagram is a triangular coordinate system; the edges of the triangle are the axes. Ternary diagrams are used to plot ...

Collective name for igneous rocks containing 90% or more mafic minerals; includes peridotites and pyroxenites. In the Earth's ...

1. Said of an igneous rock with a silica content between 45 and 52 weight-% (IUGS recommendation for the classification of ...

1. A secondary or auxiliary horizontal passage driven between levels in a mine, which may extend from a raise or stope and, ...

1. Said of an igneous rock with a silica content above 63 weight-% (IUGS recommendation for the classification of igneous ...

1. An acid is a chemical compound that produces hydrogen ions when dissolved in water. Strong or weak indicate the ...

1. Said of an igneous rock with a silica content below 45 weight-% (IUGS recommendation for the classification of igneous ...

1. Igneous rocks that contain more than 90 vol-% mafic minerals are called ultramafic. These rocks are classified by their ...