Algordanza's prices start at $3,000 for a 0.3 carat diamond. Martoia said the average order is about 0.4 to 0.5 carat, though US customers usually request bigger, 0.8-carat diamonds. But ...

The RapNet Diamond Index (RAPI™) for 1-carat diamonds — reflecting round, D to H, IF to VS2 goods — decreased 0.5% in December. The index for 0.30-carat diamonds rose 1% as improvements in D ...