Lot 58. 20.88 carats Black "Nobby" Opal with Multi-color Fire, Kelly's Field, Lightning Ridge, New South Wales, Australia. Estimate US$ 60,000 - 80,000 (€ 53,000 - 71,000). © Bonhams

With its inky, midnight black base color, this fine nodule opal displays large, broad flagstone pattern of color in chartreuse green, orange, yellow, red and electric blue. This is a notable pattern opal suitable for the knowledgeable collector. Weighing approximately 20.88 carats and measuring 25.56 x 16.47 x 7.37mm.

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