Size Large: 25mm-L x 25mm-W x 5mm-D
Size Small: 20mm-L x 20mm-W x 5mm-D
Weight: 2.9 g.
Onyx, as a name, has it's origin in Greek meaning "fingernail". This is probably because of it's weak transparency. This stone is usually banded whites, blacks and grays. Most onyx is dyed a solid color.
Mohs' Hardness Scale: 6.5
Onyx (black) works with the root chakra, which is positioned at the base of the spine. It helps in grounding ones energy. Onyx helps with self-control and eliminating excess or unwanted energies. It aids in strength, stamina, and vigor. Onyx resonates with the astrological signs Leo and Sagittarius.