"A hidden halo engagement ring is one in which a row of diamonds encircles the main gemstone from an alternative view. Often, this is a circle of smaller pavé diamonds that wrap around the main gemstone just beneath the prong tips of the ring. This results in a halo that’s only seen from the ring’s profile view, making it “hidden” when the ring is viewed from the top-down.
There are many different designs available for today’s hidden halo engagement rings including semi-halos hidden along the bottom of the ring’s gallery, gemstone halos along the shoulders, diamonds throughout the profile view of the shank or other unique combinations.
To be considered a hidden halo ring, the engagement ring should include a row of diamonds or gemstones that is seen from an alternative view of the ring rather than a standard top-down view. "