African Petrified Wood Agate 6-7mm Table Cut Cube Bead - 15-16 Inch R0861 occuring 10

occuring 10

siderophyllite

Biotite is a name used for a large group of black mica minerals that are commonly found in igneous and metamorphic rocks

but can be distinguished by its structure and its lower relative hardness

African Petrified Wood Agate 6-7mm Table Cut Cube Bead - 15-16 Inch R0861 occuring 10Petrified Wood Agate is formed from the petrifaction process of primeval trees over the course of many years. Petrification occurs when the wood is covered by sedimentary rock, as waters loosen and decompose the organic elements and replace them with silicate substances, while maintaining the wood's original structure. Preservation is enabled by a lack of oxygen.