The precious cameo brooch was made by the goldsmith Andreas Ferdinand Spiegel, active in St. Petersburg between 1830 and 1862, also known for being the teacher of Gustave Fabergé, Carl's father. Rediscovered and collected already during the eighteenth century, ancient cameos began to be used in jewelry during the Napoleonic era. In the same period, especially in Rome and Naples, where the tradition of carving shells and semi-precious stones had survived through the centuries, a production of modern cameos took on new vigor and continued with unaltered fortune throughout the century. The beauty and refinement of the sardonyx cameo, which depicts a very widespread ancient subject, the head of Minerva with her splendid helmet, led Dora Liscia Bemporad to recognize the hand of a level artist, such as the famous engraver Benedetto Pistrucci, or one of his many followers.