title: Mica polytypes: systematic description and identification.
abstract: X-ray studies of mica specimens from a variety of geological localities show that biotite and certain lithium-rich mica samples are composed of a mixture of different polytypes. Many of the biotite structures are new complex polytypes not before reported. A new method of designating mica polytypes is proposed. Techniques are described for the systematic generation of all the possible layer-stacking sequences of mica polytypes and for the verification of the stacking sequences in newly discovered forms.
authors.forename: M
authors.initials: M
authors.lastname: Ross
authors.forename: H
authors.initials: H
authors.lastname: Takeda
authors.forename: D R
authors.initials: DR
authors.lastname: Wones