By far the commonest lamellar structures occurring in calcite of Yule marble deformed at 20° to 300°C are parallel to . Some of these are recognizable as twin lamellae, but many lack definite criteria of twinning. Three types of anomalous lamellae, differing distinctly from in their angular relations to  and to other recognizable lattice directions, are also common in some deformed specimens. Lamellar structures parallel to and and cracks subparallel to have also been noted.
This paper summarized information as to criteria (appearance and crystallographic orientation) for recognition of the various types of lamellae, and the stress environments in which each tends to develop. A synopsis of this information is appended (Table 2).