You never go wrong with black gemstones in jewelry making.
Beautiful rose cut and with good polish these flat back cabochons are so ready to be transformed into amazing and elegant jewelry♥
WHAT IS BLACK ONYX:
In correct usage, the name refers to a (usually) black and white banded variety of Agate, or sometimes a monochromatic agate with dark and light parallel bands (brown and white for example) - but traditionally the name was reserved for black and white banded agate, and brown varieties named Sardonyx.
Hardness: 6.5-7 on the Mohs scale