Emerald is a gem from the Gem Homeworld, and has been around for almost as long as Rose Quartz and the other Crystal Gems (excluding Amethyst). During the time of the Rebellion, Emerald fought against Rose Quartz, fighting alongside Jasper and the other Homeworld Gems. She is known to fight with a battle axe, and her gem is placed on her chest. After the war, Emerald became quite curious as to why Rose found humans so fascinating and why she decided to protect planet Earth. However, even then she wasn't willing to go herself; being quite loyal to her homeworld.

Emerald is known to be very refined and elegant on the outside, along with very unemotional when it comes to her speaking. She doesn't act too violent or caring towards anyone or thing except protecting her own gem and her comrades. She is usually found with someone near her, hinting to her disliking being alone. However, as the gem homeworld advanced and became a bit more cruel, she began to hide in a shell of her own. In the past, Emerald was known for being very emotional and loving, highly enjoying living things. However, she was also known for her loyalty and trust, and so, remained with her planet when the rebellion struck; despite seeing Earth's beauty like Rose had.

She is usually found spending her time with Aquamarine, and Topaz, two of her closet friends that she has known since she had been "born/created". Emerald does have romantic feelings for Topaz, and cares about him, however, rarely shows this care for him whenever she is around him. She is generally good at keeping a cold and cool exterior when around other gems. Aquamarine is someone who has always been close to her, and is usually the one who chooses to stay by Emerald's side, knowing the majority of her past. Emerald also is a known acquaintance of Peridot and old friend of Jasper back during the war.

It is apparent that after Peridot and Jasper ended up becoming stuck on Earth, Emerald decided to leave for Earth to find them; using this as an excuse. Later on, Emerald does end up getting a ship to go to Earth with Topaz and Aquamarine with her. This ships later ends up crashing on Earth, leaving Emerald all by herself nearby Beach City. With no idea where her friends are, Emerald had begun to look around for her comrades, and soon ends up running into the Crystal Gems.