A crystal is a device that magically projects sounds, images, or a combination of both from afar. Circlets are portable crystal devices worn around one’s head.

Most home crystal devices resemble small pyramids with spinning stone gyroscopes on top. An array of astrate gems within the gyroscope wheels projects a glowing, moving image in the air above the device. The size and clarity of this image varies with the crystal model. Older models tend to project images with a pinkish or blueish hue, but modern crystals can project incredibly lifelike images. In addition, separate astrate gems on the base of the crystal device project sounds.

In order to function, a crystal must be attuned to a separate, distant device called an orthicon. Orthicons absorb images and sounds and magically transmit them to attuned crystal. Small orthicons can attune to only one crystal, and only over a relatively small distance. But large orthicons, such as those used by the government and mounted on citadels, can transmit to many crystals simultaneously over vast distances.

Many crystal devices have attached orthicons. Such devices allow people to look at and speak to other people in distant places, as long as their crystals and orthicons are attuned with each other. As crystal magic becomes more advanced, more and more people in Greater Akkadia use them to stay in touch with one another.

Circlets have similar magical properties to crystals, but they only project sound. Circlets are worn around the forehead. They contain a speaking-orthicon that can be attuned to a number of other circlet crystals. People use circlets to speak to friends and family over long distances, often while walking or riding canal boats.

Savants often characterize the set of all crystals as the crystal lattice, claiming that each individual crystal device can be thought of as a vertex in a greater, abstract network. People who oppose the use of crystals are often called antilatticians.