Search results
Results from the WOW.Com Content Network
Tetrahedrite gets its name from the distinctive tetrahedron shaped cubic crystals. The mineral usually occurs in massive form, it is a steel gray to black metallic mineral with Mohs hardness of 3.5 to 4 and specific gravity of 4.6 to 5.2.
Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various species. Within a mineral species there may be variation in physical properties or minor amounts of impurities that are recognized by mineralogists or wider society as a mineral variety.
Crystal healing is a pseudoscientific alternative-medicine practice that uses semiprecious stones and crystals such as quartz, agate, amethyst or opal. Despite the common use of the term "crystal", many popular stones used in crystal healing, such as obsidian, are not technically crystals. Adherents of the practice claim that these have healing ...
A crystal's crystallographic forms are sets of possible faces of the crystal that are related by one of the symmetries of the crystal. For example, crystals of galena often take the shape of cubes, and the six faces of the cube belong to a crystallographic form that displays one of the symmetries of the isometric crystal system. Galena also ...
Diaspore (/ ˈ d aɪ. ə ˌ s p ɔːr /) – also called diasporite, empholite, kayserite, or tanatarite – is an aluminium hydroxide oxide mineral, α-AlO(OH), crystallizing in the orthorhombic system and isomorphous with goethite.
Max von Laue (1879–1960): diffraction of X-rays by crystals (1912). Arthur Moritz Schoenflies (1853–1928) und Evgraf Fedorov (1853–1919): characterisation of all 230 crystal space groups (1890/91). William Lawrence Bragg (1890–1971) and William Henry Bragg (1862–1942): law on the diffraction of X-rays by crystals (1912). They are ...
Actinolite. Nephrite (var.); Adamite; Aegirine; Afghanite; Agrellite; Algodonite; Alunite; Amblygonite; Analcime; Anatase; Andalusite. Chiastolite; Andesine ...
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Pages for logged out editors learn more