Jewellery may have the designer's name on a plaque (on the back) or etched on and allso other information.
Brand signed vintage jewellery is very common. Exquisite is a brand from the company W A P Watson and so is Corocraft and Jewelcraft both from the company Coro.
Country of Origin
Often a piece of jewellery will have a signature that refers to the country of origin. Useful if that country does no longer exist as this will help with dating. Common ones found are W. Germany, Italy, Hong Kong, China, England, Japan, Czechoslovakia,
Seen on jewellery that is usually pre dating 1955 as after this date the © came into use. May have a number which can be traced and used in dating.
Many companies will have also sign their jewellery, unfortunately many modern companies do not. Avon sometimes will but mostly does not now. Marks and Spencer does nearly all the time still. Miracle nearly always did with a few exceptions. Sphinx used a mixture of signatures and 4 digit numbers. Ciro Pearls used the name Ciro or CP. However when the company was taken over in the late twentieth century the newer jewellery remained unsigned and just boxed.
Now for a question is this vintage brooch signed Sarah Coventry - is it a brand or company?
Just follow the links to see the signatures and backs to each piece of jewellery.Answer to the Sarah Coventry question will be posted in the comments shortly.