noun
tiara
tee-AR-uh/tiˈɑːrə/
A jeweled ornamental headpiece worn like a crown.
The jeweled tiara rises above its open-backed silver band.

Etymology
Greek tiara named a turban-like headdress associated with Persian kings and men of rank. The name later extended to the richly jeweled headband worn in Western fashion.
In context
Crystal, as you can see, queen for a day, wore a sparkly tiara.