Also found in: Encyclopedia.


n.1.(Crytallog.) A plane of an orthorhombic crystal which is parallel both to the vertical axis and to the shorter lateral (brachydiagonal) axis.
Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
In addition to the most common habit, two specimens show crystals bladed parallel to the b-axis (habit 2), and three loose crystals consist of the dipyramid terminated by the brachypinacoid (habit 3).