When Victoria came into power, cameos were already very popular. In 1805, a school was started in Rome called “a Prix de Rome” founded by Pope Leo XII to learn the craft of cameo engraving.
Although stone was used for the earliest cameos, shell cameos were later used to reduce its cost. Cameos were designed in rings, brooches, earrings and bracelets. Surprisingly, men also wore cameos as watch fobs, rings and pins. Onyx, agate, sardonyx, carnelian, coral, lava and jet were used to make stone cameos.
Cameos are carved out of stone by cutting away the background material to make a motif in relief. Agate was often used because of its bands of color. Engravers using stone took advantage of different layers of material to design their cameos.
Although stone cameos are more valuable than shell cameos, the really important fact is the engraving itself. Look for flowing delicate lines with fine detail. You can hold a cameo up to the light to look for cracks.
Since cameos were reset in the 1700’s and early 1800’s, it is difficult to date many cameos. Artists were very skilled at copying old designs.
If a cameo is made out of lava, it is probably Victorian. The clasp can also give its age. Safety catches were added in the 20th century. Look for solder marks as this is also a sign of later times. If a sharp pin extends past the body of the brooch, it is an old brooch.
Another way to date a brooch is to look at the material used to hold the brooch together. Gold, silver, gold filled, cut steel, jet or pinchbeck which is a mixture of brass, copper and zinc to make it look like gold were used. Pinchbeck holders of cameos date back to the 1700’s until the mid 1800’s.
In the 1840’s, gold electroplating was patented. Nine-karat gold was legalized in 1854 so a cameo that is 9k was designed during that time.