Antique Victorian Insect Brooch Tourmline Diamonds Opal 18k Yellow Gold. This is a beautiful and rare antique insect set with cabochon tourmaline eyes, rose cut diamonds and a stunning opal body. There are 11 rose cut diamonds all set in platinum. The diamonds are I color Vs-2 clarity aproxiametly .33 carats. The opal has amazing colors it is very high quality it measures 10mm by 9mm. The brooch is in excellent condition, Weight 2.9 grams, measures 22mm high by 30mm wide.