A 9ct yellow gold signet ring with a single diamond is a classic and elegant piece of jewelry. These rings feature a traditional flat top, often oval or cushion-shaped, with a small diamond typically set flush into the gold for a subtle sparkle.

The addition of a single diamond elevates the signet ring, adding a focal point and a touch of brilliance. The diamond is typically set flush into the surface (grain set or bezel set) for a smooth finish that won't snag.