Star Sapphire is less of an identity than it is a job description. It turns out that it’s a legacy thing, dating back thousands of years with a new Star Sapphire being chosen every so often when the old one dies or becomes otherwise unworthy.
Initially it was just one wackadoo space princess from the seventh dimension, but she was only a golden age irritant.
In the silver age both the space crystal and title pass on to Carol Ferris and she remained the face of Star Sapphire off and on for most of the modern age. In general, when someone refers to Star Sapphire, it is Carol they are talking about.
There are exceptions, though. In the modern era a number of folks have tried on the title for a time. Dela Pharon came to Earth to challenge for the name but lost and got sent back to space.
That’s not so bad, though; the next Star Sapphire, Deborah Darnell, also came from space, got retconned into a flight attendant and blown to smithereens.
Jillian Pearlman tried out the identity temporarily. It didn’t take but at least she got to live.
Most recently Nol-Anj, another nogoodnik from space, has taken up the gem and the title and made a nuisance of herself. Often all that these characters have in common is being thirsty for Green Lantern.
With so many options to choose from the editorial powers that be just made a whole corps of them, which really devalues the title, in my opinion.
References: [wikipedia.org: Star Sapphire (character) ]
[dc.fandom.com: Star Sapphire (disambiguation) ]
[comicvine.gamespot.com: Carol Ferris (character) ]
not[crystal]
Metahuman Database 