Meredith, it looks like you have a lovely cameo set there - congratulations! It is not uncommon for fine cameo jewelry to stay in the family for generations. Cameos are timeless. Thanks for the photo but still cannot see the pieces clearly.
The label, after enlarging the photo reads, "Genuine Cameo" - and looking at the general condition, (in the photo) this special piece, which obviously means a great deal to you, has been very well looked after and loved over the years. The cameos are black background with white relief.
Genuine Black Cameo materials are black Onyx or Black agate, possibly Whitby Jet, the latter is an organic material made from coal, but I doubt the material is Jet as jet cameo tend to be black on black.
Jet, was popular in Victoria England. The jet came from Whitby. ; there was a "mourning frenzy" in the Victorian era, due to the death of Victoria's beloved Albert. Victoria went into deep mourning, and whatever Victoria did, her loyal subjects followed. Jet is lighter than onyx so it's fairly easy to identify because of the heft (weight).
The metal is a white color, possibly silver, platinum is also white, however Plat is heavier and much harder to work with than silver - Jeweler extraordinaire Louis-Francois Cartier pioneered the use of Platinum in the 1880s.
The findings on the reverse, would indicate the age.
