Yellow Calcite 10mm Round A Grade - 15-16 Inch bicone_beads The two most popular classes

The two most popular classes of Australian Opal are Black Opal mined in Lightning Ridge and Fire Opal

Crazy Lace Agate is often dyed to produce colors that do not naturally occur in the stone

It sometimes features dark brown to black dendritic inclusions that branch like tiny tree limbs through the stone

from light blue to lapis blue to cobalt

Many stones in the Russian crown jewels from the 17th century which were thought to be rubies are actually red Tourmaline

Yellow Calcite 10mm Round A Grade - 15-16 Inch bicone_beads The two most popular classesCalcite is a rock forming mineral that is extremely common and found throughout the world in sedimentary, metamorphic, and igneous rocks. Calcite is the principal constituent of limestone and marble. These rocks are extremely common and make up a significant portion of Earth's crust.