AgAu Jewellery has dated this piece to the 1930s.

Metal: 9ct white gold.
Stone(s): 8 x Rose Cut Diamond (0.20ct) = (1.6ct) total, 1 x Amethyst (2.00ct)
Measurements: Pendant 23mm x 15mm, chain 18"/46cm
Hallmark: Pendant Unmarked, but tested for 18ct white gold, chain marked 18ct.
Weight: 5.1g
Condition: Good condition
AgAu Jewellery has dated this piece to the 1930s.
Agau jewellery offer an extensive range of 9ct and 18ct gold jewellery.
You can view the stock and full dealer information on the AgAu Jewellery Profile Page