A loupe is a magnifying device commonly used by jewelers to closely examine gemstones. It's under the loupe the gemstone reveals its quality.
Under the Loupe is also the name of an excellent blog owned and written by a fellow jewelry artist, Annette Piper, who is both talented and gracious. I met Annette on-line in my beginning days of using the WEB to promote my own jewelry business and she was very helpful to a newbie trying to keep her head above the wild waters of social/business networks.
If you like beautiful jewelry, a visit to her blog is a nice way to spend some time. From there you'll be able to jump to her website and Etsy store. Be sure to check this particular stunning piece featured on her blog!