Circa 1920’s, possibly later general’s single star with T bar and open catch.
The average WWI U.S. general officer’s star is usually seen with false embroidery, but this one is smooth like the post war, and type used for WWII stars. The pin used on this piece is the “T” bar pin (with open catch), a type used back to the Civil War days and earlier, but not much beyond the WWI era except by jewelers (that I have noticed).
British made insignia most usually have the kick (or “y”) pin, with not much deviation from that.
I am concluding to describe this star as a jeweler made piece circa 1920’s perhaps later. Although it looks to be sterling, it is not marked. This came from a recent auction; insignia from the Richard Gimbel (of the Gimbel’s Department Store family, and WWII pilot); not Gimbel’s but something acquired by him.
The star measures 22mm point to point. There are no markings.
Excellent condition. A great variant!