Gatsby Jewellery Ltd has dated this piece to the 1950s.
The pendant is on a 15.5 inch 18k yellow gold spiga wheat chain.

Cut – Round brilliant cut diamonds and a round cut ruby.
Colour – The diamonds are F.
Clarity – The diamonds are VS1.
Carat – Each of the gems is approximately 0.04 carat.
Measurements – The pendant, not including the fixed bale, is 14mm in diameter.
Weight – The pendant and chain is 9.75 grams.
Metal – Stamped 750 indicating 18k yellow gold – and tests as such.
Gatsby Jewellery Ltd has dated this piece to the 1950s.
Gatsby jewellery are a husband and wife team who have years of knowledge and experience in dealing in fine antique jewellery.
You can view the stock and full dealer information on the Gatsby Jewellery Ltd Profile Page