BOULDER MAGIC
This is a natural opal pipe pair from the jundah mine in Queensland This beautiful pair is unique as there is a layer under the opal of manganese which make the surface appear black.
The size is for the largest stone while the weight is the whole parcel

PIPE OPAL -Is crystal opal from unique pipe like structers that is usually formed in sandstone and not ironstone.. The pipes may be several centimetres in diameter and can be hollow or opal filled.They can be found in knotted masses.There formation is possibly joint controlled or they may be from zones high permeability with in the sand stone that acted as a channel for water flow.
Good luster on the stone