Of stone: having natural cleavages, with liability to split.

Mineralogy. Of fracture: Characterized by the production of small splinters.

= conchoidal, adj.

Mineralogy, etc. Applied to a fracture presenting smooth shell-like convexities and concavities.

Of a mineral: Presenting on the surface, or in the fracture, an appearance of written or printed characters. graphic gold, graphic ore, graphic tell…

Having a cleavage perpendicular to the axis.

Designating or characterized by feldspars which have crystal cleavages at an oblique angle to each other; relating to or of the nature of…

= plagioclastic, adj.