Digby Antiques (Wiltshire) has dated this piece to the 1910s.
This buckle dates to the beginning of that period.

830s silver, set with butterscotch amber, central amethyst, and chrysoprase.
Stunning piece of work and condition is excellent.
Can’t work out is there would have been another chrysoprase at the top of the buckle.
L 8.5 cm
H 6 cm
Digby Antiques (Wiltshire) has dated this piece to the 1910s.
You can view the stock and full dealer information on the Digby Antiques (Wiltshire) Profile Page