Trillion Cut Gemstones

Diamond Trilliant
Diamond Trilliant

The term trillion or trilliant is used to describe a gemstone cut that is triangular in shape. Originally, trilliant referred to a diamond cut developed by the Asscher brothers in Amsterdam. The trilliant cut was essentially an adaptation of the brilliant cut for triangular diamonds, with straight sides and usually 43 to 50 facets.

Today the names trillion or trilliant are used for all triangular gems, regardless of the faceting pattern. Even triangular cabochons are now referred to as trillions. Though the term trilliant is used to refer to triangular diamonds, trillion has become more popular for color colored gemstones.

Aquamarine Trillion 10.14 Mahenge Spinel Yellow Sapphire Trillion
Aquamarine Mahenge Spinel  Yellow Sapphire

The trillion cut can show impressive brilliance and sparkle and works very well for lighter colored gems such as aquamarine. Generally trillions are cut as equilaterals, with a 1:1 length to width ratio. 

The trillions with straight sides are typically used as side stones or accents in jewelry designs. The curved trillions are more commonly used as center stones or solitaires.

The curved trillion has a different look from the straight version. The straight trillion is all sharp points and edges while the curved version presents a softer look with curved sides and rounded points.

Trilliants are rarely used for softer or more brittle gems, such as fluorite or zircon, unless the corners are well-rounded. The tips and culets of trilliants are pointed and thin, making them liable to break. You will also find modified trillions with different proportions, usually isoceles rather than equilateral triangles. A three-sided shape which is not at least an isoceles triangle would be called a fancy shape rather than a trillion.

Rubellite Modified Trillion Gem Silica Cabochon Trillion Chrome Diopside Modified Trillion
Rubellite Gem Silica Cabochon  Chrome Diopside