Madagascar Dendiritc Green Opal 10mm Round A Grade - 15-16 Inch Green Quartz it has often been used

it has often been used as a substitute

Pink Tourmaline ranges in color from light pink to deep magenta

Glacierite has a beautiful blue color that comes from trace amounts of cobalt and vanadium

golden brown and red

Cubic Zirconia can be truly colorless

Madagascar Dendiritc Green Opal 10mm Round A Grade - 15-16 Inch Green Quartz it has often been usedThis 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.