|1.||another word for triangular|
|2.||Also: rhombohedral relating or belonging to the crystal system characterized by three equal axes that are equally inclined and not perpendicular to each other|
|trigonal (trī-gō'nəl) Pronunciation Key
Relating to a crystal having three axes of equal length intersecting at oblique angles. This crystal system is considered a subset of the hexagonal system. The mineral quartz has trigonal crystals. Also called rhombohedral. See illustration at crystal.