Onyx is the name of a black-banded gemstone and comes from the Greek onyx, meaning "claw" or "fingernail", after the stone's pale, nail-like veins. It belongs to the recent fashion for dark, edgy word names like Jet and Axel, and it was practically unused as a first name before the 2010s. Onyx entered the US top 1000 in 2018, peaked at number 307 in 2023 and ranks number 365 in 2025.