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- Leucite abstract "Leucite is a rock-forming mineral composed of potassium and aluminium tectosilicate K[AlSi2O6]. Crystals have the form of cubic icositetrahedra but, as first observed by Sir David Brewster in 1821, they are not optically isotropic, and are therefore pseudo-cubic. Goniometric measurements made by Gerhard vom Rath in 1873 led him to refer the crystals to the tetragonal system. Optical investigations have since proved the crystals to be still more complex in character, and to consist of several orthorhombic or monoclinic individuals, which are optically biaxial and repeatedly twinned, giving rise to twin-lamellae and to striations on the faces. When the crystals are raised to a temperature of about 500 °C they become optically isotropic and the twin-lamellae and striations disappear, although they reappear when the crystals are cooled again. This pseudo-cubic character of leucite is very similar to that of the mineral boracite.The crystals are white or ash-grey in colour, hence the name suggested by A. G. Werner in 1701, from 'λευκος', '(matt) white'. They are transparent and glassy when fresh, albeit with a noticeably subdued 'subvitreous' lustre due to the low refractive index, but readily alter to become waxy/greasy and then dull and opaque; they are brittle and break with a conchoidal fracture. The Mohs hardness is 5.5, and the specific gravity 2.47. Inclusions of other minerals, arranged in concentric zones, are frequently present in the crystals. On account of the color and form of the crystals the mineral was early known as white garnet. French authors in older literature may employ René Just Haüy's name amphigène, but 'leucite' is the only name for this mineral species that is recognised as official by the International Mineralogical Association.".
- Leucite thumbnail Leucite_in_rock_w-_nepheline_Potassium_aluminum_silicate_Albano_Hills_Italy_1927.jpg?width=300.
- Leucite wikiPageID "594004".
- Leucite wikiPageRevisionID "604047484".
- Leucite birefringence "δ = 0.001".
- Leucite caption "Leucite crystals in a rock from Italy".
- Leucite category Silicate_minerals.
- Leucite cleavage "Poor on {110}".
- Leucite color "White to grey".
- Leucite diaphaneity "Transparent to translucent".
- Leucite formula "K[AlSi2O6]".
- Leucite fracture "Conchoidal".
- Leucite gravity "2.45".
- Leucite habit "Commonly as euhedral, pseudocubic crystals; rarely granular, massive".
- Leucite hasPhotoCollection Leucite.
- Leucite luster "Vitreous".
- Leucite mohs "5.5".
- Leucite name "Leucite".
- Leucite opticalprop "Uniaxial".
- Leucite refractive "nω = 1.508 nε = 1.509".
- Leucite strunz "9".
- Leucite symmetry "Tetragonal 4/m dipyramidal".
- Leucite system Tetragonal_crystal_system.
- Leucite tenacity "Brittle".
- Leucite twinning "Common and repeated on {110} and {101}".
- Leucite unitCell "a = 13.056 Å, c = 13.751 Å; Z = 16".
- Leucite subject Category:Aluminium_minerals.
- Leucite subject Category:Feldspathoid.
- Leucite subject Category:Potassium_minerals.
- Leucite subject Category:Tetragonal_minerals.
- Leucite type Abstraction100002137.
- Leucite type AluminiumMinerals.
- Leucite type Material114580897.
- Leucite type Matter100020827.
- Leucite type Mineral114662574.
- Leucite type Part113809207.
- Leucite type PhysicalEntity100001930.
- Leucite type PotassiumMinerals.
- Leucite type Relation100031921.
- Leucite type Substance100019613.
- Leucite type TetragonalMinerals.
- Leucite type ChemicalSubstance.
- Leucite type Mineral.
- Leucite type ChemicalObject.
- Leucite type Thing.
- Leucite comment "Leucite is a rock-forming mineral composed of potassium and aluminium tectosilicate K[AlSi2O6]. Crystals have the form of cubic icositetrahedra but, as first observed by Sir David Brewster in 1821, they are not optically isotropic, and are therefore pseudo-cubic. Goniometric measurements made by Gerhard vom Rath in 1873 led him to refer the crystals to the tetragonal system.".
- Leucite label "Leuciet".
- Leucite label "Leucit".
- Leucite label "Leucita".
- Leucite label "Leucita".
- Leucite label "Leucite".
- Leucite label "Leucite".
- Leucite label "Leucite".
- Leucite label "Leucyt".
- Leucite label "Лейцит".
- Leucite sameAs Leucit.
- Leucite sameAs Leucita.
- Leucite sameAs Leucite.
- Leucite sameAs Leucite.
- Leucite sameAs Leuciet.
- Leucite sameAs Leucyt.
- Leucite sameAs Leucita.
- Leucite sameAs m.02tgpj.
- Leucite sameAs Q419201.
- Leucite sameAs Q419201.
- Leucite sameAs Leucite.
- Leucite wasDerivedFrom Leucite?oldid=604047484.
- Leucite depiction Leucite_in_rock_w-_nepheline_Potassium_aluminum_silicate_Albano_Hills_Italy_1927.jpg.
- Leucite isPrimaryTopicOf Leucite.
- Leucite name "Leucite".