Dr. Nagy I. Zoltán szerk.: Fragmenta Mineralogica Et Palaentologica 4. 1973. (Budapest, 1973)

90.11°. The deviation between the Mj resulting in from the optical measurements and Mj directly measured is 0.45°. In the following computions the values obtained from the optical directions will be taken into account. In the second complex the Carlsbad twinning law can be determined between the members D and E, the twinning axis is denoted by z

ir Z

IIA = - 0.20656 i + 0.78413 A + 0.585 21 k o Z - + 0.06023 i + 0.52648 j_ + 0.84891 k 0 Z

TT = - 0.20087 i + 0.78743 j + 0.58275 k llc

o The bisectrix [n

n

"j is neglected here, too, and the other two vectors are bisected. Z

TT = - 0.20372 i + 0.78579 i + 0.58399 k o Z_j and ZJJ coincide within a small limit of error, the mean value of them is taken as Z_ and this value is the basis of the further compution in both complexes. z = - 0.20316 i + 0.78674 j. + 0.58290 k —

Q — — The bisectrixes of the adequate optical symmetry axes between the members C and E are denoted by z_, z = +0.97862 i + 0.18459 A + 0.09047 k a

o z

b = + 0.97945 i + 0.18561 A + 0.07883 k o z = +0.97808 i + 0.19246 i - 0.07966 k c

o The sides of the triangle of error are: between the bisectrixes [nj andjnp] 0.87°, between pi^ and [n

Y

] 0.77° and between Jn^J and [nJI 0.36°. The unit vector computed from the arithmetical mean: z

Q = 0.97874 i + 0.18755 j. + 0.08299 k