Onyx is composed mostly of calcite (similar to limestone) and is a variety 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 a stone of strength, perseverance and endurance, according to crystal expert Satya Skynetti. “This stone can be especially useful for [people] who are moving into a new chapter in life, and they can charge it with the intention to stay resilient 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 bad moods and negativity, removing hurtful thoughts and behaviors from your life.”