2.13 Ct heart wood replacement opal Colour_Green A lovely large triangle boulder

A lovely large triangle boulder opal pair

A lovely lighter green and purple boulder opal

Sits on its side in two different directions

82 Ct wood replacement opal

A lovely large round boulder opal with a light body tone (background) and light pastel colours

2.13 Ct heart wood replacement opal Colour_Green A lovely large triangle boulderA 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