Jonty Condrup has been working in the jewellery field for over 40 years, 14 of which were spent in senior roles at Sotheby’s. In 1999, he realised a long-held ambition by starting his own private consulting business in London. Jonty Condrup works as an appraiser for jewellery and watches (including for ValueMyStuff), is a diamond broker and gemologist, and is a Registered Expert Witness (Civil) in the United Kingdom. We are very pleased that he found the time to answer a few questions.
Barnebys: As an expert jewellery valuer, you frequently handle heirlooms and therefore antique jewellery. How has the market for antique jewellery evolved?
Jonty Condrup: In addition to the 18th and 19th centuries, antique jewellery now includes pieces up to 1924, which encompasses items from the Art Deco period of 1920-1930. When it comes to the market for antique jewellery, it is essential to consider both its quality and authenticity.
See also: How Cartier Got Its Spots
The jewels in highest demand, although relatively rare, are those signed by the renowned French jewellery houses of Paris, such as Cartier, Van Cleef & Arpels, and Lalique, as they exhibit the finest craftsmanship. Rings, earrings, and pendants are the most sought after, while brooches are less desirable. Pieces made of the more durable platinum are preferred over the more fragile silver-fronted gold, which is not only less popular but also more delicate and often in need of repair.
Provenance refers to the documented history and origin of a piece of jewellery. The value of jewellery can increase significantly when it comes from renowned collections such as those of the Duchess of Windsor or Jackie Kennedy, or from other Hollywood stars or British socialites. Sometimes, black-and-white photographs featuring the jewels being worn by their owners at events like weddings, balls, or the opening of Parliament provide a highly coveted historical context.
See also: Crown Jewels: 5 Times Royal Jewellery Made Auction Headlines
An example of how the market has evolved is the increased demand for certifications for larger gemstones, i.e., 1 carat and above. Diamonds—whether white, nearly colourless, or Natural Fancy Yellow, Pink, Blue, or Green—should be certified by the GIA in New York. Rubies and sapphires should be tested to determine if they are natural or have been heat-treated to enhance their colour and clarity, and to identify their origin. The primary source for rubies is Burma, while for emeralds it is Colombia. The most prized sapphires come from Kashmir, Burma, and Sri Lanka. Emeralds may have been oiled, but ideally only slightly, and the most prestigious are accompanied by certificates of authenticity from Gubelin or SSEF (Switzerland).
Speaking of antique jewellery, tiaras are certainly exceptional pieces in this category and are occasionally offered at auctions. Why do they remain so fascinating?
Tiaras are indeed exceptionally beautiful. Traditionally, they have been worn at weddings, balls, and state occasions in the presence of the Royal Family. At public events, prominent guests could be recognised from a distance by their tiaras.
See also: Not Just for Royals: A History of the Tiara
Antique tiaras from Europe are also cherished in more distant regions. I had the pleasure of selling a magnificent tiara that was once owned and worn by Hedvig Ingeborg Madeleine, Duchess of Ortranto, née Douglas, to a client from Asia. Set with amethysts and diamonds in a platinum setting, it was created around 1910 by the court jeweller Koch (Baden-Baden, Frankfurt a. M.). The original case was also included.
Is there a particular appraisal that has stayed with you?
Speaking personally, the most interesting appraisal I’ve done was a verified 16th-century gilt bronze papal ring. Although I valued it at only around £2,000, I found it fascinating to imagine the history it might have witnessed.
