Find 18ct white gold tanzanite diamond, July Rings in Shopzilla's Jewellery & Watches category: Compare prices of 18ct white gold tanzanite diamond, July Rings and buy your new 18ct white gold tanzanite diamond, July Ring at a good price. When buying Rings, check how shoppers rated the different online shops. Simply select the store that has the Ring you're looking for. If a Jewellery & Watches store isn't rated yet it means that Shopzilla is still collecting shopper reviews.