Exhibit A: Light of the Desert Cerussite Gem

At 900 carats, this magnificent gemstone is the world's largest faceted specimen of the mineral cerussite.

Cerussite, a lead carbonate mineral, is extremely sensitive to heat and vibration—even warmth from the palm of a hand can damage it. Just imagine how much time and care the gem cutter must have taken to ensure that the inevitable heat generated during polishing and grinding wouldn’t shatter this specimen. The Light of the Desert was so named because of its dispersion (or fire) and for the deserts of Namibia, where it was found, and Arizona, where it was faceted. Dispersion, caused by the splitting of white light into the spectrum of colours, is even greater in cerussite than in a diamond. The Light of the Desert’s sheer size, precision faceting, and lack of inclusions (imperfections in the stone that inhibit the refraction of light) ensure its place as one of the world’s most spectacular gemstones.

Originally published in the Summer 2016 issue of the ROM Magazine.