The Sapphire is a common gem found in caves which emits a small amount of dim light for a few blocks. And is also the easiest ore in the game to find.It's the same texture as Diamond but darker.
The Sapphire is used to craft:
-The Sapphire Upgrade at the Portal (1 Sapphire, 40 Time Crystals)
-Sapphire Chandelier (5 Glass, 10 Sapphires)
The Sapphire isn't a very rare gem and you can find it easily in a cave.They appear to be floating when first seen and when picked, it will make a loud chime noise, louder than an Amethyst. Sapphires can also be obtained by using a Gold Pickaxe on rocks, such as Stone and Limestone.