Dr. Nagy I. Zoltán szerk.: Fragmenta Mineralogica Et Palaentologica 4. 1973. (Budapest, 1973)
A and C members = Albite (M T ) The co-ordinates of the unit vector of the Carlsbad twinning axis computed from the bisectrixes of the optical vibration directions deviate from each other only in the third decimal", thus the compution of the mean value is unnecessary. -Ic = + °' 56 4" I - 0.60797 £ + 0.55782 k o Z-p-p = + 0.56736 i - 0.60738 £ + 0.55605 k ilc o The latter value is used since it includes a right angle with the directions M-j- and MJT» "the deviation being only 0.2° and 0.27°, respectively. Kj = + 0.03484 i + 0.69222 £ + 0.72058 k o The twinning axis between the members B and E is denoted by the letter 1: 1 - - 0.38764 i + 0.39694 £ + 0.83197 k o 1. = - 0.37541 i + 0.39683 £ + 0.83761 k o 1 = - 0.37909 i + 0.40737 £ + 0.83087 k c o The arithmetical mean deviating hardly from the unit vector: 1 = - 0.38071 i + 0.40038 £ + 0.83348 k The bisectrix vector computed from the two (010) face normals: 1 = - 0.37253 i + 0.41168 £ + 0.83171 k o In the following the value computed from the optical directions will be used. The transformed values of the optical vibration directions of the twin member B:
