If you were a billionaire, what kind of jewelry would you wear? Jane and Aerin Lauder wear chic bijoux that gleam with refined aesthetics, effortless elegance, precious gems, noble metals and impeccable craftsmanship. They are the best bejeweled sisters in the U.S., if not the world. In Aerin’s case, she also designs haute luxe 24-karat yellow gold-plated costume jewelry for her AERIN brand. Her…