Polysynthetic Twinning

Polysynthetic Twinning: twinning characterized by the change of crystallographic orientation, within the same crystal, occurring with repeated and alternating reversal of direction. Also called “Multiple Twinning”, it often manifests itself in the form of a series of “twinning lamellae”.

Polysynthetic Twinning in Natural Corundum Ruby. (Photo: IGI International Gemological Institute Italy)

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