For Monica Rich Kosann, whose high jewelry collection, The Jewels of Nature, uses rare Australian black and crystal opals and ...

Aside from the widely known iridescent black and white varieties, more esoteric opals include translucent orange Mexican fire opals as well as opaque Peruvian varieties in shades of pink ...

Set with 137 beads of Mexican fire opal that are affixed to the case by ... a matte glass-blasted finish and is complemented by an orange-red carnelian dial faceted into an octagon, Mr. Genta ...