Labradorite cameo, diamond and pearl locket-brooch, circa 1890

The oval cameo carved with the profile bust of a woman in neo-Renaissance style, surrounded by rose-cut diamonds, the openwork quatrefoil frame decorated with floral sprigs of rose-cut diamonds and accented with pearls at the quarters, the reverse with glazed locket compartment, mounted in gold. 

Nice carving detail to the cameo, the pearls have very good luster and minute blemishing, diamonds are of decorative quality. With glazed compartment on the reverse. In good condition.
In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective qualified opinion. Illustrations in the catalogue may not be actual size. Prospective purchasers are reminded that, unless the catalogue description specifically states that a stone is natural, we have assumed that some form of treatment may have been used and that such treatment may not be permanent. Our presale estimates reflect this assumption.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING CONDITION OF A LOT, ALL LOTS ARE OFFERED AND SOLD "AS IS" IN ACCORDANCE WITH THE CONDITIONS OF SALE PRINTED IN THE CATALOGUE.

The labradorite cameo in the present brooch is likely the work of Wilhelm Schmidt (1845-1938) originally from Idar in south-west Germany, a town known for mineral and gemstone trading, agate polishing and engraving. At the age of 15, he was sent to a cousin's workshop in Paris where he first learned the art of cameo cutting from the master Arsène whose idealized classical style had more in common with works of Renaissance masters than the art of the ancients. After the outbreak of the Franco-Prussian war, Wilhelm and his brother Louis, a mineral importer, emigrated to London and set up a business at Hatton Garden. The move was well timed given the prosperity of Victorian England and the popularity of  'archaeological' jewelry that resulted in a demand for engraved gems.  Schmidt was known for his skill in carving unusual stones such as labradorite and claimed to have invented a new and difficult technique for carving opal and opal matrix.