origin of antique bracelet

by kathy Andersen
(New Zealand)

I have inherited a bracelet. It is yellow gold with rose gold embellishing the top with 3 inset amethysts.The base is rolled gold & double tracked.The clasp is a slide in one with a safety chain.

It has I believe got the letters D&Co 9ct on the inside, if my vision is correct!? I wonder if it is Victorian?