Briolette cut stones are unique in having surfaces comprising only triangular facets. When buying a 2.2-carat diamond ring studded with a briolette-cut diamond, you would need to watch the following things.
Diamond Briolette Holes
There are briolette-cut diamonds which carry a hole at or near the top. This normally reduces the value of such a stone but is an acceptable characteristic nevertheless. Many briolette-cut diamonds require the presence of a hole, which allows inserting a chain since these can also be used in pendants and bracelets. If you were buying it for a ring, however, a hole that is visible from the surface would be unsightly, so it is best to pay extra for a stone that does not have one.
The briolette cut carries significant beauty, especially if it is cut in a way as to exude superb brilliance. Go for one of the Excellent, Very Good, and Good cut grades, which would get you a drop-shaped diamond with a narrow top and a roundish base. A lesser grade would noticeably lack in brilliance, but if it is all you can afford, leave the option open while you continue searching.