Prices for superior-quality diamonds of half carat and above reflected higher profit margins. However, smaller sizes, mainly 30 pointers, were weak.%%The overall index, which encompasses all sizes between 0.3 carats and 3 carats, rose 2.6% to 128.7 points, an increase of 2.7% on the year so far.%%Fine quality one carats and Fine half carat diamonds were the strongest performers, gaining 8.9% and 11.9% respectively.%%The index further reflected that thirty pointers, or 0.3 carats, weakened.