Diamond Old European Collet Set Drop EarringsFred Leighton diamond old european collet set drop earrings in yellow gold. The Fred Leighton Round is a proprietary diamond cut that perfects the understated elegance and charm of antique diamonds with modern engineering. Based on the old European cut that reigned from 1890 1930, the Fred Leighton Round is more brilliant than a vintage stone, dazzling with fire and charisma. Here, we feature the unique cut in earrings inspired by the Georgian era,