Yellow Calcite 10mm Round A Grade - 15-16 Inch bicone_beads Ruby and Sapphire

Ruby and Sapphire

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

from light blue to lapis blue to cobalt

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

orange and rust are due to traces of hematite within the stone

Yellow Calcite 10mm Round A Grade - 15-16 Inch bicone_beads Ruby and SapphireCalcite 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.