This piece of Libyan Desert Glass weighs 18.5 carats and is 9 mm x 16 mm x 31 mm.
The so called Libyan Desert Glass is the purest natural silica glass ever found on earth. The glass is generally yellow in color. It can be very clear or it can be a milky, and even contain tiny bubbles, white wisps, and inky black swirls. Over a thousand tons of these glass are strewn across hundreds of kilometers of bleak desert. Most of these are the size of pebbles polished smooth by the abrasive action of the blowing sand. Others are chunks of considerable size and weight. The biggest piece ever found weighed around 26 kg.