We all know about the Kate effect on fashion. Anything the Duchess of Cambridge wears, particularly if purchased from a High Street store, is an instant sell out. So it’s no wonder that the High Street is getting style inspiration from the stylish Duchess. One of my fave jewellery brands, Jon Richard, has put its on spin on one of Kate’s most iconic items, the glorious sapphire and diamond engagement ring. This piece of jewellery once belonged to the Princess of Wales, and sparked a resurgence in larger, more traditional style rings when William presented it to his bride-to-be. Many jewellery brands have produced their own copy of the Kate…