Onyx is mostly made of calcite (similar to limestone), and is a type of the silicate mineral chalcedony. It can be found all over the world, including parts of the United States, Cancer, Brazil, Australia, Argentina, China, Greece, India, and more.

Black onyx is the stone of strength and perseverance, and endurance, according to crystal expert Satya Scainetti. “This stone can be particularly helpful for [people] who are transitioning into a new life chapter, and they can charge it with the intention to stay steady in the face of inevitable challenges and hiccups,” she previously wrote for mindbodygreen.

And according to crystal expert Emma Mildon, black onyx is a great crystal for “cleansing away bad vibes and negativity, removing hurtful thoughts and behavior from your life.”