The coupon is not valid on “persona” items or clearance/sale items.
Here is a link to search results for jewelry under $100. It will take you directly to page 5, where the cheapest qualifying jewelry (including a silver and a tungsten ring) appears to start at $45. If you find any qualifying jewelry under $45 please leave a comment. Remember that if it says “persona” in the title or is on sale the coupon won’t work.
A $45 ring will be just $25 with free shipping in your cart.
Post what jewelry you’ll be buying in the comments!