allomorph
  同質異晶; 同質異象變體
  al·lo·morph /ˈæləˌmɔrf/ 名詞
  Al·lo·morph n.  Min. (a) Any one of two or more distinct crystalline forms of the same substance; or the substance having such forms; -- as, carbonate of lime occurs in the allomorphs calcite and aragonite. (b) A variety of pseudomorph which has undergone partial or complete change or substitution of material; -- thus limonite is frequently an allomorph after pyrite.
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  allomorph
       n 1: any of several different crystalline forms of the same
            chemical compound; "calcium carbonate occurs in the
            allomorphs calcite and aragonite"
       2: a variant phonological representation of a morpheme; "the
          final sounds of `bets' and `beds' and `horses' and `oxen'
          are allomorphs of the English plural morpheme"