As a general rule, any carved cameo made from a natural material can be considered authentic. Some of the materials used include shell, agate, carnelian, onyx, ivory, lava, coral, jet, bone, mother of pearl, and various gemstones. A cameo is referred to as being non-authentic or fake if it has been made with plastic or resin.
Soft plastics chip easier than shell, porcelain, and stone do. Hard resins are fairly chip-resistant, though. This speaks more to the cameo’s value rather than its authenticity. A chipped cameo might be real, but these signs of damage will cause its market value to decline.
Since figures on authentic vintage cameos can face in any of these three directions, this alone is definitely not an indication of authenticity. If you have other reason to doubt whether or not the cameo is real, though, the fact that the figure faces left or forward instead of right, as is most common, could give you further reason for doubt.
Portrait cameos that have a straight nose are usually from the Victorian era. Portraits with strong, “Roman” noses are usually dated before the 1860s. A nose that looks “cute” or button-like usually indicates a newer cameo created in the 21st century. If the nose is turned up and the features are flat, it could be a sign that the cameo is fairly modern and likely created with lasers, making it non-authentic.
With a “c-clasp,” the brooch pin loops under a crescent shaped piece of metal. There is no roll-over fitting there to keep the end in place.
Note that some detail can actually indicate when a piece is fake. For instance, many laser cut imitations have a faint white band near the outer border of the piece. Some authentic cameos will be set in 14K or 18K gold frames. Silver and gold filled metal frames are also common. This is not always the case, however, and many have no settings at all. These frames may also be further decorated with valuable stones, but this, too, is not always true.
This is not always true, however, so weight alone is not a good indication of authenticity. Many stone cameos are naturally heavier than their shell and porcelain counterparts, as well.
This is true of most carved cameos, in fact, since many natural materials are difficult to buff after being carved. Some authentic stone cameos might be slightly shiny, however, so this is not a foolproof test.
Shells have a naturally curved surface, so a cameo carved from a shell will usually have this curve, as well. The curve might be slight, though. This does not necessarily apply to natural carved cameos made from stones or other materials, though.
Note that this is not true of most stone cameos. While somewhat rare, some plastic cameos are similarly thin and may show the silhouette, as well. As a result, this is not a foolproof test when done on its own.
This is true for all naturally carved cameos. Carve marks will usually follow the lines and curves of the design. Scratches that do not appear to follow these lines are usually just scratches and should not be perceived as an indication of authenticity.
You could also hold the cameo to your wrist or chin. These areas are generally a little cooler than the palm of your hand and may give you a more accurate indication.
In contrast, a cameo that sounds fairly solid is likely made of stone or another natural material. Be careful when performing this test. Do not strike the piece against your teeth too hard since doing so could damage your tooth or the cameo.
Note that many modern resins are too hard and will not be melted that easily, though, so the test may not work. Work carefully to prevent an accidental burn while handling the hot needle. Wear heat-proof gloves or hold the needle with plastic tweezers.
The quality of paint and enamel used by vintage artisans is usually more durable than that used by counterfeit manufacturers nowadays. Real cameos were made to last, so the design should be fairly intact. This is also an indication of value. Scratched designs cause the value of the cameo to decrease.
As a general rule of thumb, if the painting and the piece itself looks sparkling new, it probably is.
Even though there should be few scratches that are obvious with the naked eye, you should be able to see some faint scratches all along the surface under this sort of magnification.
