Cut "a Trillion" is a modification of the brilliant cut, combining the diamond with a triangular shape in projection onto the plane of the girdle. Depending on the characteristics of the cut to distinguish the varieties of "trilliant", "triangle", "Trigon". Trillion cut is usually the total number of faces from 31 to 52.Standardized in a form "Trilliant pyatidesyatimetrovy (T-52)" has 25 faces of the crown (1 face pad, 6 faces an upper triangular wedges of the crown, 6 of the main faces of the crown in the shape of a rhombus and deltoid, 12 faces of the lower pair of wedges in the form of a triangle) and 15 of the pavilion facets (3 main facets of the pavilion in the form of deltoid and 12 wedges of the pavilion in the shape of a triangle), the other 12 have facets cut on the surface of the girdle.

More precisely, a weight is determined taking into account the amendments on the thickness of the girdle, bulge cut, size caletta, the ratio of the proportions of the cut.

Initially, the form of a "trillion" was developed in 1962, the company "Henry Meyer Diamond Company" from new York (USA). Creating the cut "trillion" is attributed to nameless masters of Holland of the late 1960-ies – early 1970-ies.