The skull in depiction is a good way of understanding whether or not a mourning jewel is all it claims to be. As a collector, one has to be careful that there is no room for error when buying a piece, this is often overlooked, as many pieces can interest just due to their beauty and not their fact.
With this particular piece, one must make two assumptions; the skull is rendered contemporary for its time, but not as part of its original construction or that it is a much later addition to deceive or promote financial gain.
This is a difficult spot for the collector. Upon first examination, the ring looks remarkably correct in its style. The skull is an obvious anachronism, for it to be part of mainstream fashion when the ring is estimated to be constructed would make it an anomaly. However, the rest of the ring, with its black enamel shoulders and 1st quarter 19th century rectangular hair memento are seemingly correct.
Hence it comes down to the style of the skull being the only things we can take from it. Skull design in mourning jewels can be identified easily enough through matching detail with mainstream art and contemporary pieces. In this case, the skull is simply rendered, which does conform with earlier skulls, but isn’t definitive.
Highly detailed skulls, that you may see on modern rings would automatically default this piece to be a poor addition, but if this is modern or not can’t be discounted.
Perhaps one should question the taste in adding a skull to the remnants of a loved one, when this is the last element of the person that is left, especially in a time when the memento mori motifs were out of fashion.
Regardless, it is the curiosity in jewellery that makes it fun to discover. Each tells a tale, each resonates with personal history.