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  2. Carbonatite - Wikipedia

    en.wikipedia.org/wiki/Carbonatite

    Carbonatite (/ kɑːrˈbɒnəˌtaɪt /) is a type of intrusive or extrusive igneous rock defined by mineralogic composition consisting of greater than 50% carbonate minerals. [ 1 ] Carbonatites may be confused with marble and may require geochemical verification. Carbonatites usually occur as small plugs within zoned alkalic intrusive complexes ...

  3. Sovite - Wikipedia

    en.wikipedia.org/wiki/Sovite

    Specimen 7.5 cm) Sovite (or sövite) is the coarse-grained variety (or facies) of carbonatite, an intrusive, igneous rock. The fine-grained variety of carbonatite is known as alvikite. [1] The two varieties are distinguished by minor and trace element compositions. [2] Sovite is often a medium-to-coarse-grained calcite rock with variable ...

  4. Tephra - Wikipedia

    en.wikipedia.org/wiki/Tephra

    Tephra is any sized or composition pyroclastic material produced by a explosive volcanic eruption and precise geological definitions exist. [2] It consists of a variety of materials, typically glassy particles formed by the cooling of droplets of magma, which may be vesicular, solid or flake-like, and a varying proportions of crystalline and ...

  5. Panda Hill Carbonatite - Wikipedia

    en.wikipedia.org/wiki/Panda_Hill_Carbonatite

    The Panda Hill Carbonatite is an apatite and pyrochlore bearing sovite carbonatite located in the Mbeya District of Tanzania. The deposit was found in the mid-1950s by the then Geological Survey of Tanganyika (now Tanzania). Niobium ore occurs largely in pyrochlore bearing sovite (carbonatite composed largely of calcite) and dolmite -rich ...

  6. Wöhlerite - Wikipedia

    en.wikipedia.org/wiki/Wöhlerite

    None. Wöhlerite, also known as wöehlerite [2] is a member of the amphibole supergroup, and the wöhlerite subgroup within it. It was named after German chemist Friedrich Wöhler. It was first described by Scheerer in 1843, but the crystal structure was later solved by Mellino & Merlino in 1979. Once approved, it was grandfathered by the IMA.

  7. Carbonate - Wikipedia

    en.wikipedia.org/wiki/Carbonate

    A carbonate is a salt of carbonic acid, H2CO3, [ 2 ] characterized by the presence of the carbonate ion, a polyatomic ion with the formula CO2−3. The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate groupO=C (−O−)2.

  8. Category:Carbonatite occurrences - Wikipedia

    en.wikipedia.org/wiki/Category:Carbonatite...

    Pages in category "Carbonatite occurrences". The following 10 pages are in this category, out of 10 total. This list may not reflect recent changes .

  9. Mean free path - Wikipedia

    en.wikipedia.org/wiki/Mean_free_path

    The atoms (or particles) that might stop a beam particle are shown in red. The magnitude of the mean free path depends on the characteristics of the system. Assuming that all the target particles are at rest but only the beam particle is moving, that gives an expression for the mean free path: ℓ=(σn)−1,{\displaystyle \ell =(\sigma n)^{-1},}