Commonly used to refer to valuable stones or decorative items.
El anillo que le regaló es un joyo invaluable para ella.
The ring he gave her is an invaluable jewel for her.
Ese anillo es un joyo que mi abuela me dejó como herencia familiar, y siempre lo llevo puesto.
That ring is a jewel that my grandmother left me as a family heirloom, and I always wear it.