2.51 Ct heart wood replacement opal Type_Single A lovely green and purple

A lovely green and purple boulder opal pair that really sparkle in the sun

A very pretty green-blue boulder opal

10 mm thick

if you are after a matching heart set

2.51 Ct heart wood replacement opal Type_Single A lovely green and purpleA beautiful 2. 51 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