noun

carbuncle

A deep red gemstone, especially a garnet.

A deep red carbuncle gleamed in the ring.

Etymology

Latin carbo means coal, and the diminutive makes a little coal. A deep red gemstone received that name because its rich color suggested a glowing ember.

More examples

  • The old inventory listed a silver brooch set with a carbuncle.
  • The jeweler identified the carbuncle as garnet.
  • Candlelight brightened the polished carbuncle.

Forms

carbuncle · carbuncles

Similar words

garnet
Garnet is a mineral group; carbuncle is an older name for certain deep red gems, often garnets.
ruby
Ruby is a specific mineral variety; carbuncle is a historical descriptive gem term.