Onyx Studs may refer to:
- The accessory from Final Fantasy Crystal Chronicles: Ring of Fates.
- The accessory from Final Fantasy Crystal Chronicles: Echoes of Time.
Onyx is a banded variety of chalcedony. Agate and onyx are both varieties of layered chalcedony that differ only in the form of the bands: agate has curved bands and onyx has parallel bands. The colors of its bands range from white to almost every color (save some shades, such as purple or blue). Commonly, specimens of onyx contain bands of black and/or white.