An carat Black Opal purchased by Richard Krementz in Lightning Ridge, Australia. Courtesy of Richard Krementz Gemstones. Photo by Robert Weldon/GIA (Gemological Institute of America) via Dieter Rosenkranz
Uncut Raw Blue Amber: "Blue amber is the rarest of all ambers, and before the Indonesian discovery it was only found in the Dominican Republic and in small quantities in Mexico, and Sumatra. Less than of all the amber recovered is of blue color.