Another lovely ring from my moms huge collection. Possibly amethyst, peridot, citrine, blue topaz and garnet. CID is the hallmark for Jewelry Maker Clyde Duneier, Inc. of New York. This mark was first trademarked in 1991 and was cancelled by 1997. A famous jewelry making firm in New York since 1910, this mark was created for their line of fine jewelry expressly created for high-end department stores. I’ve included a photo of a listing for the same ring style valued at $595. I’ve also seen them listed for less. If you’re looking for a size 10 at a reasonable price, here it is. I’d rather keep this than accept an insulting lowball offer.