A Trillion cut (sometimes called Trilliant, Trillian or Trielle) is a triangular type of gemstone cut. It has many variations with curved or uncurved sides. The shape of the table at the top of the ring also varies.
For solitaires, a curved or convex cut is employed, whereas accent stones are cut uncurved or concave. Additional variations include round-cornered triangular, modified shield cuts and triangular step cuts. Normally, Trillion cuts are reserved as side stones to accent larger solitaire stones in engagement rings (usually square or rectangular shaped stones). But Trillions also make for a perfect solitaire stone themselves considering their stunning brilliance and fire.
The Trillion cut comprises of three equal sides and 31 or 50 facets depending on whether the diamonds are used as solitaires or accent stones. The trillion’s unique style has great fire and displays sharp brilliance if the stone is cut to the correct depth. A well cut Trillion can also hide any inclusions in the stone well.
The Trillion cut can trace its history back to the 1400’s when ‘Pendeloque’ or ‘Briolette’ cuts were first developed in Amsterdam. In 1962, the Henry Meyer Diamond Company of New York designed and trademarked the modern Trillion cut and over time the trillion became the generic name for all triangular brilliant cut diamonds.