Lot 51. 21.77 carats Crystal Opal with Multi-Color Fire, Lightning Ridge, New South Wales, Australia. Estimate US$ 35,000 - 45,000 (€ 35,000 - 44,000). © Bonhams A large oval cabochon crystal opal with slight potch to the underside having a rolling flash...

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...

Lot 114. 41 carats Black Opal with Floral Pattern Red Play of Color, Lightning Ridge, New South Wales, Australia. Estimate US$ 70,000 - 80,000 (€ 62,000 - 71,000). © Bonhams A large and impressive "nodule" opal (a nobby), having an incredible pinfire...