LAS VEGAS–(BUSINESS WIRE)–Robust retail sales are driving positive sentiment in the diamond market. Polished prices continue their upward momentum even as inventory levels gradually rise in some sizes. Steady demand, shortages in certain categories and high rough costs are supporting prices. The RapNet Diamond Index (RAPI™) for 1-carat diamonds climbed 2.7% in June. RapNet Diamond Index (RAPI™) June 1HJan. 1 to Jul. 1 Y2YJul. 1, 2020, to Jul. 1, 2021 RAPI 0.30 ct. 0.5% 1.0% 8.8% RAPI 0.50 ct.