Lady's 18K White Gold Blue Topaz & Diamond Ring. Ring Size: 8 (Can be Resized to Fit Most Any Finger.) Contains: One Natural Fancy Cut Topaz. Weight Approx: 20.00ct, Color: Blue, Origin: Brazil. Forty-Eight Natural Round Brilliant Cut Diamonds. Weight Approx: .20cttw, Color: G-H, Clarity: SI. Complementary 18K White Gold 20.00ct Blue Topaz & Diamond Pendant Available. Click Here! A spectacular Brazilian fancy cut Natural Blue Topaz, with a weight of approximately 20ct, surrounded by 48 perfectly matched round, high in white color, diamonds. This is a low price for such a beautifully made, large stone.