The Collaborative International Dictionary
Rhombohedral \Rhom`bo*he"dral\, a. (Geom. & Crystallog.) Related to the rhombohedron; presenting the form of a rhombohedron, or a form derivable from a rhombohedron; relating to a system of forms including the rhombohedron and scalenohedron.
Rhombohedral iron ore (Min.) See Hematite.
Rhombohedral system (Crystallog.), a division of the hexagonal system embracing the rhombohedron, scalenohedron, etc.
Wiktionary
a. (context crystallography English) Having three equal axes and oblique angles.
WordNet
adj. having three-fold symmetry [syn: trigonal]
Usage examples of "rhombohedral".
Outwardly this formation resembled quartz in that it crystallized in the trigonal trapezohedral class of the rhombohedral subsystem of hexagonal symmetry.
It is rhombohedral in crystallization and isomorphous with calcite and chalybite.
As in the other rhombohedral carbonates, the crystals possess perfect cleavages parallel to the faces of the rhombohedron.