onyx

noun

1. Mineralogy. a variety of chalcedony having straight parallel bands of alternating colors.Compare Mexican onyx.
2. (not used technically) an unbanded chalcedony dyed for ornamental purposes.
3. black, especially a pure or jet black.
4. Medicine/Medical. a nail of a finger or toe.

adjective

5. black, especially jet black.

noun

1. a variety of chalcedony with alternating black and white parallel bands, used as a gemstone. Formula: SiO 2
2. a compact variety of calcite used as an ornamental stone; onyx marble. Formula: CaCO 3

n.mid-13c., from Old French oniche “onyx” (12c.), and directly from Latin onyx (genitive onychis), from Greek onyx “onyx-stone,” originally “claw, fingernail” (see nail (n.)). So called because the mineral’s color sometimes resembles that of a fingernail, pink with white streaks. n.

1. unguis
2. A collection of pus in the anterior chamber of the eye.

1. A type of chalcedony that occurs in straight and parallel bands of different colors, often black and white.