sapphire

nouns

a precious transparent stone of rich blue corundum valued as a gemstone
sapphire
is a type of (narrower)
very hard mineral used as an abrasive
corundom, corundum
is a type of (narrower)
a gemstone having the property of transmitting light without serious diffusion
transparent gem
a transparent piece of sapphire that has been cut and polished and is valued as a precious gem
sapphire
is a type of (narrower)
a precious or semiprecious stone incorporated into a piece of jewelry
gem, jewel, precious stone
a light shade of blue
azure, cerulean, lazuline, sapphire, sky-blue

adjectives

of something having the color of a blue sapphire
"sapphire eyes"
sapphire
is similar to
being or having or characterized by hue
chromatic