Blue Agate: History, Meaning, Healing Properties & Benefits One of the few gemstones that embodies inner beauty is blue agate. Before we begin our discussion on blue agate, let's discuss what agates are. Agates are a variety of chalcedony. From the surface, or from outside, they look distasteful and less desirable. However, when these stones are cracked open, you will discover a beautifully banded and vividly patterned interior. This interior of agate has bright colors as well as banded shapes. Because of this beauty, these agates are used in making gemstone jewelry, like blue agate jewelry.