they could be genuine cultured pearls. My best advice without having the benefit of a photo to see them and to determine if they are genuine cultured pearls or imitations would be to follow the drill hole. The clasp that says "Made in England" - provides a little clue date - and would indicate an earlier date with a reference to the Act of the Union.
The UK became the United Kingdom of Great Britain and Northern Ireland in the 1920s (1922) following the independence of five-sixths of Ireland as first the Irish Free State, a Dominion of the then British Commonwealth, and then later as an independent republic outside the British Commonwealth as the Republic of Ireland. You can read more about the Act of the Union on the following page: http://www.britroyals.com/union.htm
Lisa you can also find more information about imitation pearls at the following link: https://www.antique-jewelry-investor.com/pearl-imitation.html
