An obsolete term for chromian muscovite.
An obsolete term for chromian muscovite.
An obsolete term for a halloysite from Angleur, Belgium.
In mining, the non-economic host rock in which valuable minerals (usually metalliferous ore minerals) are found. When the gangue is discarded, this material is referred to as “tailings”.
A modulated 2:1 layer silicate with a continuous octahedral sheet and a tetrahedral sheet that involves triple chain strips linked by pairs of inverted tetrahedra that connect the strips and adjacent layers (Eggleton and Guggenheim, 1986). The ganophyllite chemical composition is approximately (K,Na,Ca)6(Mg,Fe,Mn)24(Si32.5Al7.5)O96(OH)16. 21H2O. The large cations (K, Na, Ca) are exchangeable and occur associated near the undersaturated inverted tetrahedra that connect adjacent layers. Eggletonite is the Na analogue of ganophyllite. Ganophyllite occurs in low-grade metamorphic, silicate-rich manganese deposits, such as those found at the Harstig mine, Pajsberg, near Persberg, Vermland, Sweden.
A dioctahedral member of the true/brittle mica group with the ideal chemical composition of [Ba0.5(Na,K)0.5]Al2(Si2.5Al1.5O10(OH)2. Ganterite may be described as a Ba- dominant analogue of muscovite-2M1 that crystallizes, like most muscovite crystals, in space group C2/c. Ganterite was originally described from basement rocks of the Berisal Complex, Simplon Region, Switzerland (Graeser et al., 2003). but it has also been found from Oreana, Nevada, and Ba-rich muscovite-like phases have been reported from West Greenland; Ontario, Canada; and Franklin/Sterling Hill, New Jersey, USA.
A group of orthosilicate (= nesosilicate) minerals with stoichiometry of A3B2(SiO4)3, where divalent cations occur in the large-size (8-coordinated) A site and trivalent cations occur in the medium-size (6-coordinated octahedron) B site. Common garnet minerals are pyrope [Mg3Al2(SiO4)3], almandine [Fe3Al2(SiO4)3], spessartine [Mn3Al2(SiO4)3], uvarovite [Ca3Cr2(SiO4)3], grossular [Ca3Al2(SiO4)3], and andradite [Ca3Fe2(SiO4)3]. These garnets are separated into two series, pyralspite (the Mg, Fe, and Mn Al-rich members) and ugrandite (the Ca-rich members). Solid solution is common in the A site of pyralspite and in the B site of ugrandite, but little substitution between the two series. Grandite is a generic name for the grossular-andradite series. Garnet minerals commonly occur in metamorphic rocks, and are believed to be stable in the lower mantle of the earth. The minerals are generally cubic (= isometric) in symmetry. Garnet minerals are generally hard (Mohs hardness H: 6.5 to 7.5) and dense (specific gravity G: 3.5 to 4.5) and are used commercially as an abrasive.
Syn., silicate garnet
Although not a valid mineral name, garnierite is often used as a field term for nickel-bearing (± magnesium) hydrous phyllosilicates.
A small mineral concretion in the stomach. Some gastroliths may form if excess (ingested) clay cannot be eliminated by the digestive system. Some species, such as birds, reptiles, or dinosaurs, swallow small stones (gastroliths) that are believed to aid in digestion. These gastroliths are generally not concretions and are rounded and polished owing to the abrasive action within the stomach.
An obsolete term for a variety of talc that apparently deviates from the (OH) content of talc as determined in old literature, from Gava valley, Italy.
A measure of the ability of a colloidal system (i.e., a gel or sol) to withstand a load (shear force) without loss of the high slurry viscosity and/or the mechanical elasticity, often measured with a rheometer and expressed in units of mass per area. The gel strength is a function of the inter-particle forces present in the solid-liquid system.
Cf., colloid, suspension, gel, sol