The trilliant cut is a triangular type of gemstone cut. This cut is also known as a trillion or trillian and has many variations. The original trilliant cut was introduced by the Asscher brothers in Amsterdam and later trademarked by the Henry Meyer Diamond Company of New York in 1962. But ever since the patent has expired, the term “Trilliant cut” is used to refer to all triangular shaped gems. This is a fairly unusual cut, but can sometimes be seen in solitary jewelry pieces as an accent gem.