Hi we need to see an image of the mark and the bracelet. have you any idea how old the bracelet is? there are quite a lot of star symbols, on precious metals. 750 is the standard of gold fineness. more common in Europe.
As your Bracelet is made of 18 karat gold, which indicates high quality, you might like to consider getting it appraised. the expert will also be able to help you out with information about the marks. images of the mark and the bracelet will be necessary for a Jewelry Appraisal through Antique Jewelry Investor. Images are sent through after completing the Jewelry Appraisal Form.