4.28 Ct wood replacement heart opal Type_Pipe A very large and rare

A very large and rare boulder opal from our Mt

A large green-blue opal that reminds us of the reefs and tides

47 Ct triangle boulder opal with gem-grade rainbow stripes

Sits on its side in two different directions

4.28 Ct wood replacement heart opal Type_Pipe A very large and rareA lovely 4. 28 Ct wood replacement heart opal. What is Wood Replacement opal? Opal formation commences when silica dissolves in water. At our Russells opal mine we have found that this silica solution occupies a void most probably left by decaying tree roots or branches. In cases where the silica infiltrates organic material before complete decomposition occurs, the organic molecules are replaced by silica. This remarkable process results in the