Onyx

Onyx is the name of a gemstone, a type of chalcedony with alternating  parallel bands, as well as used to refer to a jet-black color. It comes from Latin onyx via Ancient Greek ónux (claw, nail, fingernail) deriving from a PIE root word. Origin: Proto-Indo-European Variants: Onix (English, Spanish) Ónix (Spanish)  

Onika

Onika is an African female name though there doesn’t seem to be a lot of accurate information on it. I’ve seen it with various meanings of “warrior”, or it could be derived from Yoruba meaning “one in possession of”, or it could be a short form of Onyekachi, an Igbo name meaning “who is greater than…