Lot 58. 36.92 carats Midnight Black Opal with Red and Green Pattern Cathedral Window, Lightning Ridge, New South Wales, Australia. Estimate US$ 55,000 - 65,000 (€ 49,000 - 58,000). © Bonhams

This stunning "nobby" opal cabochon (nodule opal) has a midnight black base color with a "cathedral window" patterned effect of broad patches of vivid green, vermilion red, orange and yellow. Such large opals with a rich saturation of color are now difficult to find in the marketplace. Weighing approximately 36.92 carats and measuring 32.0 x 20.0 x 8.0mm.

Bonhams. The World of Gold, Opals and Other Phenomenal Gems, Los Angeles, 30 June 2020, 10:00 PDT