Dating gold jewellery
The early C clasp continued to be very popular and was used on jewelry up until the early 1900s when the safety catch was invented .
Earlier C clasps had the longer pins and those used closer to the invention of the locking C clasps had shorter pins as the fabrics became less thick.
If you have a piece of jewelry with a more modern clasp that you believed to be an older period piece, then take a good look at the clasp and links surrounding the clasp.
If they are slightly different metal or make than the body of the piece, you likely have a replaced clasp.
The famous story ends with Archimedes running through the streets shouting "eureka, eureka" after he found a means to expose the deceit while he sat in a bath tub.
Sometime around the turn of the 20th century, the locking C clasp was invented.