Premier American collection
 of twelve lightning ridge black opals, Lightning Ridge, New South Wales, Australia . Estimate US$ 600,000 - 800,000 (€560,000 - 740,000). Photo Bonhams.

Comprising a free-form black opal, weighing approximately 11.07 carats; an oval black opal, weighing approximately 12.12 carats; an oval black opal, weighing approximately 13.0 carats; a free-form semi-black, weighing approximately 14.0 carats; a free-form black opal, weighing approximately 14.12 carats, an oval black opal, weighing approximately 18.98 carats; a free-form semi-black opal, weighing approximately 22.64 carats; a free-form semi-black opal, weighing approximately 45.63 carats; a kite-shaped black opal, weighing approximately 54.75 carats;
a heart-shaped, semi-black opal, weighing approximately 61.75 carats; another heart- shaped semi-black opal, weighing approximately 62.05 carats; and a free-form black opal, weighing approximately 167.93 carats.
 The individual descriptions of opals are listed below as lots 1100A-K . Total aggregate carats weight: 498.04 carats. (12)

Bonhams. THE WORLD OF OPALS, 23 Nov 2015 15:00 PST - LOS ANGELES