In modern times, onyx has been found in Scotland, Canada, the US, Madagascar, India, Germany, Czech Republic, Russia, China, and Brazil.
Astrologically speaking, onyx, specifically black onyx, is the birthstone for Leo. Metaphysically, onyx is said to encourage one to take responsibility for self-improvement, as well as self-mastery; it's associated with determination as well as protection.
Black onyx wire pendant created by Frances (Fenya) Lediaev