"Gem" was the name chosen by Dr. McCoy for a mute humanoid empath from a planet in the Minarian star system. In 2268, she was tested by a race called the Vians to see if her people were worthy to be saved from a supernova that was threatening her planet. The Vians had the power to save one species. However, she overcame her fears and offered her life to save McCoy's. The Vians healed McCoy and, taking Gem with them, teleported from the laboratory. The Vians determined that her people were worth saving, and her planet was spared from destruction. (TOS: "The Empath")