In geometry terms the difference between diamond and triangle
is that
diamond is the polyiamond made up of two triangles while
triangle is a polygon with three sides and three angles.
As nouns the difference between diamond and triangle
is that
diamond is a glimmering glass-like mineral that is an allotrope of carbon in which each atom is surrounded by four others in the form of a tetrahedron while
triangle is a polygon with three sides and three angles.
As proper nouns the difference between diamond and triangle
is that
diamond is {{given name|female|from=English}} of modern usage, from the name of the gem while
Triangle is the area comprising the cities of
Raleigh,
Durham and
Chapel Hill in
North Carolina. Used with "the" except when attributive.
As an adjective diamond
is made of, or containing diamond, a diamond or diamonds.
As a verb diamond
is to adorn with or as if with diamonds.