7.2 ct opal boulder Freeform- 3.99 g - (2)

Two Boulder opal gems totaling 7.2 carats. They are set in 925 silver. They originate from Queensland, Australia. This opal is one of the most fascinating, beautiful and sought-after in the world. The iron host rock does not separate from the gem, forming a single, indivisible piece. They were formed through an exceptional geological process that took millions of years, during the Cretaceous period. Water rich in siliceous minerals penetrated cracks in the host rock; this water slowly dried, crystallizing into micro-spheres of silicon dioxide, giving rise to the opal stuck to the host rock where it formed. Its characteristic shine occurs when light penetrates these perfectly ordered micro-spheres, producing the diffraction of light. A wonderful optical prism-like effect that generates that impressive play of colors. Customs charges outside the EU will be borne by the auction winner.

Estimate:£125.67

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