Vintage Brooch/ Pendant with Oval Blue Stone, Diana/Kate

This piece appears to be a reference to the Princess Diana/Kate Middleton engagement ring. I've had it since the late 1990s, so I'd say it was the former. A faceted blue oval stone is set amid a halo of round sparkling rhinestones, in silver tone metal. It can be worn as a brooch or as a pendant. The size is are 1.25" long.