Trilliant Diamond

The trilliant was developed in Amsterdam in the 1960s, though triangular diamonds have existed in various forms since the 18th century. The modern trilliant uses a modified brilliant facet pattern adapted to a triangular outline, creating a stone that returns light aggressively for its size. Trilliants come in two main variations: pointed corners (common for side stones set in protective prong settings) and curved/rounded corners (preferred for center stone use, as the slight curves reduce chipping risk). Both variations feature 31 to 50 facets depending on whether they are standard or modified brilliants. The triangular shape means trilliants face up significantly larger than rounds of the same carat weight. A 1-carat trilliant appears roughly 20% larger face-up than a 1-carat round. This makes them particularly attractive for buyers who want maximum visual impact per carat. The trade-off is that depth and pavilion geometry in a triangle are harder to optimize, so poorly-cut trilliants can show windowing (transparency) or dark areas. In the trade, trilliants are most commonly seen as side stones flanking emerald cuts, Asschers, or radiants. A matched pair of 0.25-0.50ct trilliants is one of the classic three-stone combinations in engagement ring design.