The Ruby is a rare gem found in caves which emits a small amount of dim light for a few blocks.
The Ruby is used to craft:
-The Ruby upgrade at the portal (1 Ruby, 80 Time Crystals)
-Ruby Pickaxe (5 Rubies, 80 Time Crystals)
-Ruby Chandeler (5 Glass, 10 Rubies)
The Ruby is a rare gem and you need a lot of time to find it in a cave. They appear to be floating when first seen and can be mined as you would pick up an item, it will then make a loud chime noise. Rubies can also be obtained using a Gold Pickaxe on rocks, such as Stone and Limestone.