Septarian Gemstone Crystal Egg 1 us size 5 Australian Boulder Opal Ring |

Australian Boulder Opal Ring | 925 Silver

Great design from Julio ~ lovely detail on the feathered wings

Whilst not a tremendously rare stone

Face of nugget approx 18 x 33 mm

Face  21 x 33 mm

Septarian Gemstone Crystal Egg 1 us size 5 Australian Boulder Opal Ring |Septarian Gemstone Egg Septarian is a concretion of rock, formed from a calcium rich clay that hardened into a limestone nodule. Later, the rock shrank, creating cracks that were then filled with water in which calcite crystal formed. The angular cracks are called septaria which comes from the Greek word septum meaning partition. That Calcium rich clay was originally the bed of an Ocean so the source of the Calcium was Marine Life. The Brown crystals