Solange Azagury-Partridge, Londoner and self-proclaimed control freak, taught herself about jewelry design and turned a mere hobby into a luxury brand. Over the last 20 years, she’s created some of the most innovative and sought-after jewelry, with clients like Victoria Beckham stopping by her Notting Hill boutique. She talks to BlackBook about the opening of her New York store, why you should buy diamonds when you can't pay your mortgage, and designing her own engagement ring.