The Pearl of Great Price was the object of a story about a merchant recounted by Montgomery Scott. The merchant, who when he found one pearl of great price, went and sold all that he had and bought it.
Scott referred to the story when he was told of Gem and the Vians, comparing Gem to the pearl. Captain Kirk acknowledged the comparison and noted that "whether the Vians bought her or found her makes little difference – she was of great value." (TOS: "The Empath")