This is a rhodium plated, adjustable ring hand set with a large druzy quartz stone.
The quartz has been coated in metalic vapour by a process called vapour deposition to give it its metallic look. It is primarily a dark blue but also has purple tones.
Smallest size - UK - N, US - 7, FR - 55.
It will expand by about one - two sizes.
These are natural stones, therefore each ring will look slighty different. Approx. stone size - 27 x 30mm