(IDEX Online) - A spectacular yellow-brown diamond fetched $325,000 in the first online-only sale of diamonds by Christie's.The Jewels Online: Summer Sparkle realized $1,492,625 in total, with 84 per cent sold by lot.The headline lot was a 20.21-carat pear-shaped stone (pictured) set in a fine white diamond necklace. Other highlights included old mine brilliant-cut diamond ring of 12.02 carats, which realized $118,750; a diamond ring of 4.80 carats that sold for $87,500; and a fancy yellow diamond ring of 8.16 carats, which achieved $81,250.Christie's say the sale (August 12-27) attracted 28 per cent new registrants from over 20 countries.