trigonal

As an adjective trigonal

is symmetrically triangular.

As a noun chladniite is

(mineral) a colourless trigonal mineral.

As an adjective trigonal

is symmetrically triangular.

As a noun spherocobaltite is

(mineralogy) cobalt(ii) carbonate, a red trigonal mineral used in pottery glazes.

As an adjective trigonal

is symmetrically triangular.

As a noun berborite is

(mineral) a colorless trigonal or hexagonal mineral, with chemical formula be₂(bo₃)(oh,f)·(h₂o).

As an adjective trigonal

is symmetrically triangular.

As a noun kutnohorite is

(mineralogy) a rare calcium manganese magnesium iron carbonate mineral with trigonal crystals, having a white, pink or brown colour.

As an adjective trigonal

is symmetrically triangular.

As a noun aerugite is

(mineral) a rare complex nickel arsenate mineral that forms green to deep blue-green trigonal crystals.