al2o3

4 definitions found

al2o3 - Collaborative International Dictionary of English v.0.48 :

  Sapphire \Sap"phire\ (? or ?; 277), n. [OE. saphir, F. saphir,
     L. sapphirus, Gr. ?, of Oriental origin; cf. Heb.
     sapp[imac]r.]
     1. (Min.) Native alumina or aluminium sesquioxide, Al2O3;
        corundum; esp., the blue transparent variety of corundum,
        highly prized as a gem.
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              Of rubies, sapphires, and of pearl['e]s white.
                                                    --Chaucer.
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     Note: Sapphire occurs in hexagonal crystals and also in
           granular and massive forms. The name sapphire is
           usually restricted to the blue crystals, while the
           bright red crystals are called Oriental rubies (see
           under Ruby), the amethystine variety Oriental
           amethyst (see under Amethyst), and the dull massive
           varieties corundum (a name which is also used as a
           general term to include all varieties). See Corundum.
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     2. The color of the gem; bright blue.
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     3. (Zool.) Any humming bird of the genus Hylocharis, native
        of South America. The throat and breast are usually bright
        blue.
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     Star sapphire, or Asteriated sapphire (Min.), a kind of
        sapphire which exhibits asterism.
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  Sesquioxide \Ses`qui*ox"ide\, n. [Sesqui- + oxide.] (Chem.)
     An oxide containing three atoms of oxygen with two atoms (or
     radicals) of some other substance; thus, alumina, Al2O3 is
     a sesquioxide.
     [1913 Webster] Sesquipedal

  Alumina \A*lu"mi*na\, n. [L. alumen, aluminis. See Alum.]
     (Chem.)
     One of the earths, consisting of two parts of aluminium and
     three of oxygen, Al2O3.
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     Note: It is the oxide of the metal aluminium, the base of
           aluminous salts, a constituent of a large part of the
           earthy siliceous minerals, as the feldspars, micas,
           scapolites, etc., and the characterizing ingredient of
           common clay, in which it exists as an impure silicate
           with water, resulting from the decomposition of other
           aluminous minerals. In its natural state, it is the
           mineral corundum.
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  Corundum \Co*run"dum\ (k[-o]*r[u^]n"d[u^]m), n.; pl. Corundums
     (k[-o]*r[u^]n"d[u^]mz). [Also corindon.] [From Hind. kurand
     corundum stone.] (Min.)
     The mineral alumina (Al2O3), as found native in a
     crystalline state. Transparent varieties are used as
     gemstones, including sapphire, which is the fine blue
     variety; the oriental ruby, or red sapphire; the oriental amethyst
     , or purple sapphire; and adamantine spar, the
     hair-brown variety. It is the hardest substance found native,
     next to the diamond.
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     Note: The name corundum is sometimes restricted to the
           non-transparent or coarser kinds. Emery is a
           dark-colored granular variety, usually admixed with
           magnetic iron ore.
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