A plane of an orthorhombic crystal which is parallel both to your vertical axis and also to the reduced lateral brachydiagonal axis
- A plane of an orthorhombic crystal that will be parallel both towards the vertical axis and the shorter horizontal (brachydiagonal) axis.
(letter.) An airplane of an orthorhombic crystal which can be parallel both towards straight axis and the shorter lateral (brachydiagonal) axis.
Crystals are prismatic, acicular or scaly in habit; they have a perfect cleavage parallel to the brachypinacoid (M in the figure).