Madagascar Dendiritc Green Opal 10mm Round A Grade - 15-16 Inch Green Quartz The shell is often found

The shell is often found naturally polished with a green or brown spiral on one side and a white "eye" on the other

and many others

Discovered in 1910 on the west coast of Tasmania

com originate in the Philippines or Indonesia

black with a golden sheen

Madagascar Dendiritc Green Opal 10mm Round A Grade - 15-16 Inch Green Quartz The shell is often foundThis variety of opal is named "dendritic" for the small inclusions within it that resemble moss or ferns. These inclusions consist of iron, manganese and other metallic oxides captured during the forming of the rock. Opals are hydrated amorphous forms of silica, created when silica hardens within the fissures of other stones.