(The opinions expressed in this article represent the views of PolishedPrices, an independent news and price list provider to the diamond industry and should not be seen as reflecting the Views of Reuters)



The main PolishedPrices index opened down 2.9% from the previous week on Monday at 158.3 points. The overall index is currently 26.2% above its level of this time last year, and has gained 20.5% since the start of the year.



Most benchmark categories slipped into negative territory, after posting modest gains in the previous week.



Commercial 0.5 carats were the worst performers, falling 8.3%.  Mixed and Commercial 1.0 carats recorded losses of 7.4% and 5.6% respectively.  Best performers were Fine 0.5 carats, gaining 1.6% during the week.



Mixed quality 0.5 and 0.3 carats traded in narrow ranges, showing virtually no changes from the previous week.