Mindat.org Glossary of Mineralogical Terms

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• rhizolith
  Rhizoliths are organosedimentary structures formed in soils or fossil soils (paleosols) by plant roots. They include root moulds, ...
• ferrimagnetic
  Synonym of ferrimagnetism
• ferrimagnetism
  i. Unbalanced orientation of magnetic moments. Intermediate between ferromagnetism and antiferromagnetism.Ref: Van ...
• ferromagnetic
  Ferromagnetism is the property of materials that are attracted by a magnetic field; an applied magnetic field creates an induced ...
• paramagnetic
  Having a small positive magnetic susceptibility, but not retaining any magnetisation like ferromagnetic materials. A paramagnetic ...
• diamagnetic
  Diamagnetism is the property of materials that are repelled by a magnetic field; an applied magnetic field creates an induced ...
• ophiolite suite
  An ophiolite is a sequence or association of rocks representing a section of Earth's oceanic crust and the underlying upper ...
• graphitoid
  i. An adjective synonymous with: graphitic ii. Meteoritic graphite: Graphitoid (of Shepard)
• micaceous
  i. Consisting of or containing mica; e.g., a micaceous sediment.ii. Resembling mica; i.e., thinly foliated.
• chondrule
  A chondrule (from Ancient Greek χόνδρος chondros, grain) is a round grain found in a chondrite. Chondrules form as molten ...
• dioctahedral
  Said of layered silicates (Phyllosilicates) having two-thirds of the voids in the octahedral layer filled, generally with ...
• trioctahedral
  Pertaining to a layered mineral structure of the kaolinite-serpentine group, pyrophyllite-talc group, Smectite, mica, or chlorite ...
• kelyphytic rim
  A type of corona texture, a term mostly applied to reaction rims in metamorphic rocks, usually consisting of microcrystalline ...
• kelyphytic
  See kelyphitic rim
• mimetolith
  A stone bearing a fancied resemblance to something familiar such as a face, animal, landscape scene, etc. Perceiving such a ...
• molasse
  i. A partly marine, partly continental sedimentary facies consisting of a thick sequence of fossiliferous conglomerates, ...
• persistent
  Continuous; orebodies are often persistent in depth and metal contents.Ref: von Bernewitz
• permitted
  .See: permitted explosive, permitted light
• raise
  A vertical or inclined opening in a mine driven upward from a level to connect with the level above, or to explore the ground for ...
• décollement
  Detachment structure of strata owing to deformation, resulting in independent styles of deformation in the rocks above and below. ...
• fault
  i. A fracture or a fracture zone in crustal rocks along which there has been displacement of the two sides relative to one ...
• pyrite oxidization
  Synonym of pyrite decay
• pyrite decay
  Pyrite decay, commonly known as pyrite disease, is the oxidation of iron sulfide and some other non-iron sulfide minerals, a ...
• pyrite rot
  Synonym of pyrite decay
• harpolith
  A harpolith is a large, sickle-shaped igneous intrusion interpreted as a phacolith that has been strongly deformed, typically ...
• pyrite oxidation
  Synonym of pyrite decay
• pyrite disease
  Synonym of pyrite decay
• quarry
  A quarry is a site where stone, rock, sand, gravel, or other non-metallic materials are extracted, most commonly by open ...
• mining district
  A mining district is a geographically defined area in which mineral extraction has occurred on a significant and often sustained ...
• national landscape
  In the United Kingdom, National Landscape is the modern designation for areas formerly known as Areas of Outstanding Natural ...
• national park
  A National Park is a protected area designated to conserve natural landscapes, wildlife, and cultural heritage, while also ...
• epitaxy
  i. Induced orientation of the crystal lattice of an electrodeposit at the plane of contact with the undisturbed underlying ...
• counter-septarian
  Counter-septarian structure is a shrinkage phenomenon that occurs near the surface of a nodule or a planar surface such as a ...
• septarium
  i. A large, roughly spheroidal concretion, generally 8 to 90 cm in diameter, usually of an impure argillaceous carbonate, such as ...
• usambara effect
  The Usambara effect is a phenomenon where a gemstone exhibits color differences due to variations in thickness in different parts ...
• mud crack
  i. An irregular fracture in a crudely polygonal pattern, formed by the shrinkage of clay, silt, or mud, generally in the course ...
• megacryst
  A crystal or grain that is considerably larger than the encircling matrix (usually > 1 cm). They are found in igneous and ...
• phenocryst
  A term for large crystals (megacrysts) or mineral grains floating in the matrix or groundmass of an igneous rocks (often ...
• hypergenetic
  Hypergenic processes refer to changes that occur at the Earth's surface due to factors like weathering, erosion, and water ...
• laccolith
  A concordant igneous intrusion with a known or assumed flat floor and a postulated, dike-like feeder commonly beneath its ...
• phacolith
  A concordant intrusive in the crest of an anticline and trough of a syncline; in cross section, it has the shape of a doubly ...
• pockmarks
  Ubiquitous seafloor depressions formed by the fluid/gas seepage through marine sediments.Pockmarks associated with cold seeps ...
• fossil
  i. Any remains, trace, or imprint of life that has been preserved in the Earth's crust since some past period of geologic time. ...
• impact crater
  An impact crater is an impact-related, approximately circular depression with raised rims on the surface of a planet, moon, or ...
• mineral resin
  Any of a group of resinous, usually fossilized, mineral hydrocarbon deposits; e.g., bitumen and asphalt.See also: resin
• protist
  A protist or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus.
• palynomorph
  Palynomorphs are the microscopic, acid-resistant organic remains and debris produced by a wide variety of plants, animals, and ...
• cryptospore
  Microscopic fossilized spores produced by embryophytes (land plants). They first appear in the fossil record during the middle of ...
• miospore
  Microscopic spores and pollen, a term generally used for spores smaller than 200 μm. Both cryptospores and miospores are types ...
• stamp mill
  An apparatus, and the building containing it, in which rock is crushed by descending pestles (stamps), operated by water power or ...