The Survey Says…Platinum Guild International recently revealed results of its 2011 Independent/Small Chain Jewelry Retailers Sentiment Study of Platinum Bridal Jewelry. Produced by GfK Retail and Technology, the study offers insights into sales among 201 (or 17 percent) of PGI’s Preferred Partners Program, plus 202 small chain and independent U.S. stores.A few findings won’t be a surprise: Partner stores (part of a PGI-organized sales and marketing support program) sell significantly more platinum bridal jewelry than nonpartners. And while white gold is the best-selling metal, responsible for more than half of all sales, platinum accounts for nearly a third.Engagement rings compose the majority (63 percent) of platinum ­jewelry sales in stores surveyed, followed by women’s wedding rings (20 percent). Meanwhile, 61 percent of ­jewelers surveyed said “entry platinum” products