2.13 Ct heart wood replacement opal Colour_Green blue and grey boulder opal

blue and grey boulder opal specimen

A lovely large triangle boulder opal pair

A beautiful black boulder opal with bright greens and blues

A lovely boulder opal heart with a great stripy pattern

A lovely lighter green and purple boulder opal

2.13 Ct heart wood replacement opal Colour_Green blue and grey boulder opalA lovely 2. 13 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