polysynthetic twinning

2 definitions found

polysynthetic twinning - Collaborative International Dictionary of English v.0.48 :

  Polysynthetic \Pol`y*syn*thet"ic\
     (p[o^]l`[i^]*s[i^]n*th[e^]t"[i^]k), a. [Poly- + synthetic.]
     Characterized by polysynthesis; agglutinative.
     [1913 Webster]
  
     Polysynthetic twinning (Min.), repeated twinning, like that
        of the triclinic feldspar, producing fine parallel bands
        in alternately reversed positions.
        [1913 Webster]

  Twinning \Twin"ning\, n. (Crystallog.)
     The assemblage of two or more crystals, or parts of crystals,
     in reversed position with reference to each other in
     accordance with some definite law; also, rarely, in
     artificial twinning (accomplished for example by pressure),
     the process by which this reversal is brought about.
     [1913 Webster]
  
     Polysynthetic twinning, repeated twinning of crystal
        lamellae, as that of the triclinic feldspars.
  
     Repeated twinning, twinning of more than two crystals, or
        parts of crystals.
  
     Twinning axis, Twinning plane. See the Note under Twin,
        n.
        [1913 Webster]