Mindat.org Glossary of Mineralogical Terms
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- stratiformi. Said of a special type of strata-bound deposit in which the desired rock or ore constitutes, or is strictly coextensive with, ...
- concordanti. Said of intrusive igneous bodies, the contacts of which are parallel to the bedding or foliation of the country ...
- nebuliticThe texture characteristic of a nebulite, with mineralogical zones having indistinct boundaries.
- stickingi. A small vein (a scrin) not wide enough for shoulder room, Derbyshire, U.K. Ref: Arkell ii. The selvage of mineralized ...
- serpentinizationThe process of hydrothermal alteration by which magnesium-rich silicate minerals (e.g., olivine, pyroxenes, and/or amphiboles in ...
- serpentinisation
- eocambrianThe term "Eocambrian" refers to a geological time period that is not officially recognized in the standard global geological time ...
- parallel growthTwo or more crystals with corresponding faces parallel due to continuous alignment of their crystal structures. Ref: Fay
- parallel drumA cylindrical form of drum on which the haulage or winding rope is coiled. The drum roll may be plain or grooved. For deep winds, ...
- mammillaryOf, or pertaining to, smoothly rounded masses resembling breasts or portions of spheres; descriptive of the shape of some mineral ...
- mamillary
- fossickeri. A person who searches for small amounts of minerals. Ref: CTD ii. One who picks over old mine workings. Fossicking is ...
- septariumi. A large, roughly spheroidal concretion, 8 to 90 cm in diameter, usually of an impure argillaceous carbonate, such as clay ...
- boulderi. A detached rock mass larger than a cobble, having a diameter greater than 10 in (25.4 cm) or 8 phi units, or about the size of ...
- tabulari. Said of a feature having two dimensions that are much larger or longer than the third, such as a dike, or of a geomorphic ...
- platyA crystal habit where it is plate-shaped: relatively thin but broad in two other dimensions. Compare tabular; platy usually ...
- internal castSolid matter that filled the interior of a fossil shell or other organic structure and preserves the form of the interior cavity. ...
- steinkern
- internal mold
- microlitesMicrolites are minute crystals in an amorphous matrix. In igneous petrology, the term microlitic is used to describe vitric ...
- tabby extinctionA gemmological term for an optical effect under cross polarisation. The (polariscope) pattern due to anomalous double refraction ...
- superconductivityThe abrupt and large increase in electrical conductivity exhibited by some materials at very low temperatures. Ref: ASM, ...
- tablei. See: rotary table Ref: Weed, 2 ii. In placer mining, a wide, shallow sluice box designed to recover gold or other ...
- tabbyi. A mixture of lime with shells, gravel, or stones in equal proportions, with an equal proportion of water, forming a mass that ...
- conservationConserving, preserving, guarding, or protecting; keeping in a safe or entire state; using in an effective manner or holding for ...
- slickensideA slickenside is a fault surface that can vary from highly striated to a smoothly polished surface caused by frictional movement ...
- striationi. See: stria ii. One of multiple scratches or minute lines, generally parallel, inscribed on a rock surface by a geologic ...
- slickenfibre Slickenfibres are mineral fibres that grow along slickenside during fault movement,
- striatedAdj. of striation.
- tabular depositA flat table-like or stratified mineral deposit or sedimentary bed; e.g., a coal seam. See: tabular Ref: Nelson
- 4d-stemScanning electron nanodiffraction (SEND), a method that captures electron diffraction data for each position scanned by the ...
- bunkerA vessel for the storage of materials; the lowermost portion is usually constructed in the form of a hopper. Also called ...
- pastingThe operation of mudcapping or plaster shooting whereby rock is blasted without drilling. An explosive is placed on top of the ...
- volcanic bombAn ellipsoidal, discoidal, or irregularly rounded mass of lava ejected at a high temperature during a volcanic eruption. Bombs ...
- spheroidal weatheringA form of chemical weathering in which concentric or spherical shells of decayed rock (ranging in diameter from 2 cm to 2 m) are ...
- raman spectroscopyRaman spectroscopy relies upon inelastic scattering of photons, known as Raman scattering. A source of monochromatic light, ...
- pyroclastAn individual particle ejected during a volcanic eruption. It is usually classified according to size: Ash: 64mm, rounded and ...
- lapilliPyroclasts (loose volcanic fragments), that may be either essential, accessory, or accidental in origin, of a size range between ...
- homeotypicTwo crystal structures are considered as homeotypic if all essential features of topology are preserved between them, despite ...
- peloidPeloids are allochems (visible grains >0.5mm) in limestones that are composed of micrite ( very fine grained carbonates, mostly ...
- intraclastIntraclasts are irregularly-shaped grains or clasts that form by syndepositional erosion (i.e. erosion simultaneous with ...
- pelletPellets, a type of peloid, are small spherical to ovoid or rod-shaped grains that are common component of many limestones. They ...
- baveno law twinA type of simple contact twin on the {021} plane exhibited by orthoclase, microcline and other members of the feldspar ...
- homeotypeA mineral is considered a homeotype of another if their crystal structures are homeotypic.
- breadcrust bombA breadcrust bomb is a volcanic bomb with a cracked and checkered surface, sometimes resembling the surface of a loaf of bread. ...
- trichroismCharacteristic of a crystal showing three different colours when rotated in polarised transmitted light; limited to ...
- dichroismi. A type of Pleochroism shown by a uniaxial crystal, which is indicated by two different colors or two shades of the same ...
- polarised
- dichroicA mineral, gem or other material showing dichroism, I.e. different colours when viewed in different directions.
- opacitic rim