Potomac Crystal Trilliant Fancy Stones - Colorshift Blue Emerald. The crystal trilliant is a machine cut,triangular shaped, fancy stone with multiple facets that rise to a flat top surface. The crystal has a foiled back to enhance light reflection and bring more sparkle to your projects. The trilliant has no hole and is designed for bezeling with seed beads or wire. Have fun getting creative and adding extra interest and glamour to your designs. The Potomac Crystal Trilliant Fancy Stone can be used in designs calling for Swarovski Trilliant 4706. They measure 17mm and come in a pack of 2.