In a play about William Dewey, he was saved by an unknown Fusion Gem from a Gem Monster. Little is known about her except for a very basic idea of her physical appearance based on the silhouette from the play.
Her lower body and upper torso appear to be reminiscent of Garnet. She also sports a huge mane of hair but kept in a proper hairstyle closely resembling that of Rose Quartz. She is depicted with four arms, while the temple fusion has eight arms, and Alexandrite has six.
In the play, she is portrayed as towering over William Dewey, his ship and its crew. Whether or not this is an actual attribute of hers or simply an artistic choice by Jamie remains unknown. However, the script used was edited by Pearl for accuracy, as she had first-hand experience.
In Mayor Dewey's script, his ancestor performed the actions of this Fusion Gem.
Mayor Dewey describes his ancestor as growing to fifty feet tall. (15.24 meters)
Being that Jamie had to make the prop of the fusion in a short amount of time, the fact that it has 4 arms could just be that Jamie either was not told its amount of arms or he didn't have time.