• Spinel group - Wikipedia

    en.wikipedia.org/wiki/Spinel_group The space group for a spinel group mineral may be Fd 3 m (the same as for diamond), but in some cases (such as spinel itself, MgAl 2 O 4) it is actually the tetrahedral F 4 3m.. Normal spinel structures are usually cubic close-packed oxides with eight tetrahedral and four octahedral sites per formula unit. The tetrahedral spaces are smaller than the octahedral spaces. B ions occupy half the ...
  • Spinel group | mineralogy | Britannica

    www.britannica.com/science/spinel-group The spinel-group minerals have type XY 2 O 4 and contain oxygen atoms in approximate cubic closest packing. The cations located within the oxygen framework are octahedrally (sixfold) and tetrahedrally (fourfold) coordinated with oxygen ...
  • Spinel Group | Definition of Spinel Group by Merriam-Webster

    www.merriam-webster.com/dictionary/spinel%20group Spinel group definition is - a group of mineral oxides including the spinel series and having the general composition AB2O4 in which A represents magnesium, ferrous iron, zinc, or manganese or any combination of them and B represents aluminum, ferric iron, or chromium.
  • Mineral Gallery - The Spinel Group

    www.galleries.com/Spinel_Group The Spinel Group contains over twenty members, but only a few are considered common. They are a group of oxides that have very similar structures. Named after their sole gemstone representative, spinel, this is an important group of minerals. It includes one of the most important ores of iron, magnetite; an important ore of chromium, chromite, an important ore of lead, minium; a once important ...
  • Spinel Group | An Introduction to the Rock-Forming ...

    pubs.geoscienceworld.org/books/book/952/chapter/106864782/Spinel-Group The spinel group has the general formula A 2+ B 3+ 2 O 4.Many elements may enter the spinel cubic close-packed structure. Among naturally occurring spinels, A may be Mg, Fe 2+, Zn, Mn, Ni, Co, Cu and Ge, whereas B may include Al, Fe 3+, Cr, V and Ti.Materials with the spinel structure are of considerable importance to the electronics industry
  • Spinel group — Wikipedia Republished // WIKI 2

    wiki2.org/en/Spinel_group Spinel group From Wikipedia, the free encyclopedia The spinels are any of a class of minerals of general formulation AB 2 X 4 which crystallise in the cubic (isometric) crystal system, with the X anions (typically chalcogens , like oxygen and sulfur ) arranged in a cubic close-packed lattice and the cations A and B occupying some or all of the ...
  • Spinel Group: Mineral information, data and localities.

    www.mindat.org/min-29156.html A non IMA-approved group name, in use in literature before 2018, for cubic oxides of general formula AE 2 O 4.These species were sub-divided into three series: Spinel series (E = Al), Magnetite series (E = Fe), and the Chromite series (E = Cr).
  • Spinel | mineral | Britannica

    www.britannica.com/science/spinel Spinel, mineral composed of magnesium aluminum oxide (MgAl 2 O 4) or any member of a group of rock-forming minerals, all of which are metal oxides with the general composition AB 2 O 4, in which A may be magnesium, iron, zinc, manganese, or nickel; B may be aluminum, chromium, or iron; and O is oxygen.The spinel group is divided into three immiscible series: the spinel (aluminum-spinel) series ...
  • Spinel - Wikipedia

    en.wikipedia.org/wiki/Spinel Spinel (/ s p ɪ ˈ n ɛ l /) is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula MgAl 2 O 4 in the cubic crystal system.Its name comes from the Latin word "spinella", which means spine in reference to its pointed crystals.
  • Spinel: Red and blue gemstones confused with ruby or sapphire

    geology.com/minerals/spinel.shtml The Ruby and Sapphire Impostor. Spinel is a gemstone mineral that has been confused with ruby and sapphire for over 1000 years. Several of the most spectacular spinels ever discovered have been mounted in "crown jewels" and other "jewelry of significance" under the assumption that they were rubies or sapphires.