The Jewel Stars was a stellar cluster of eight stars located over 100 light years from Argelius II. This cluster was located somewhere in the Alpha or Beta Quadrant.
In 2364, the location of The Jewel Stars was labeled in a star chart that was filed in the USS Enterprise-D library computer. (TNG: "Datalore", "Conspiracy", display graphic)
This stellar cluster was only mentioned in writing.
This star chart was originally drawn by Rick Sternbach for the Star Trek Spaceflight Chronology (p. 133), where they were indicated to be a tourist destination. The dashed lines on the map indicated "starliner routes".