Jewellery detective on trail of Yorkshire's hidden gems

Jewellery is fetching record prices as interest rates and sterling remain low. Simon Mitchell, Yorkshire's '˜jewellery detective', is on a mission to find the hidden gemshiding in your attic.

Simon MItchell.

Simon Mitchell is Bonhams’ jewellery expert for the North East and he has more than 40 years of experience in the business. As such, he has come across some true gems which, for many of their owners, have been life-changing. “It may look like a bag of granny’s old costume jewellery, but you never know what might be in there of value,” he says.

“It is a fantastic feeling when someone brings something in and you really think it is something special, and then it fetches a really good sum at auction, often more than you estimated.”

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One such example was a Chanel necklace that had been inherited by a lady in Ilkley.

Although not the most valuable piece Mitchell has ever sold, it was one of his most memorable and also favourite pieces.

“She knew that it was signed Chanel but other than that knew nothing about it. I had a feeling it was a very rare piece of vintage Chanel jewellery but it was in quite a poor state. We did think about having it restored before sale but decided against it due to the cost implications.”

Mitchell put a conservative estimate of £4,000-£6,000 on the necklace and sent it down to Bonhams’ New Bond Street auction house – where it fetched £68,500 (including buyer’s premium)

“The lady told me for her that amount of money was life-changing. For me it was such a rare piece that I doubt I will ever see one again.”

Another memorable lot was found in a bank vault in Northumberland wrapped in a newspaper and inside what looked like an old PE pump bag.

“I really had no idea what it was but it was clear it had great potential,” admits Mitchell. “It was a finial of a tiger’s head, very ornate, gilded with rubies, diamond and emeralds.It was clearly an important find.”

As with all antique jewellery, the provenance is key and so Mitchell set about trying to establish the finial’s authenticity.

He traced it back through the family and it turned out to be a finial taken from the throne of Tipu Sultan of Mysore dating back to 1787 - 1793.

“Something like that doesn’t come along everyday.” The tiger’s head sold for £389,600 bought by an overseas bidder.

There has been a ‘meteoric’ rise in the value of top-quality jewellery and gemstones recently, much fuelled from overseas markets such as China, India and the Middle East.

One example was an Art Deco jade ring that came into the Leeds office of Bonhams which has now moved to Bowcliffe Hall near Wetherby.

“It was a lovely piece but its value depended on the quality of the jade and its rarity and so we decided to send it for testing,” explains Mitchell, who put an estimate of £3,000 to £4,000.

“We also decided to send it to Hong Kong to be sold where it raised more than £52,000, but all that was down to the fact that we had a certificate authenticating the rarity and quiality of the jade.”

This increase in prices for rare gemstones is being widely seen says Mitchell and, as a result, Bonhams has launched a campaign to help owners understand the worth of their jewellery and guide them on achieving the best prices if they decide 
to sell.

Coloured diamonds, sapphires, rubies and emeralds, as well as fine pieces of jewellery from key eras like the 1920s and 1930s, have enjoyed unbroken price rises over the past decade. These include a 970 per cent price increase for sapphires; a 1,100 per cent increase for rubies and a 1,900 per cent price increase for emeralds.

Prices for Art Deco (1920s and 1930s) and Belle Époque (1890 to 1915) jewellery have soared by 72 per cent since 2007.

Antique jewellery has risen by 54 per cent and jewellery from the post-war era (1945-1975) has risen by 89 per cent during the same period according to data released by Art Market Research.

Such rises mean many owners may be sitting on jewellery they rarely wear or may have inherited that is worth far more than they realise.

“We are offering a free valuation service,” says Mitchell. “People can email us pictures of their jewellery or they can make an appointment to bring it in.”

However, he does warn that he isn’t always the bearer of glad tidings.

“It is often the case that people have had a valuation done for insurance which is far higher than the valuation for sale purposes. It means that sometimes people are disappointed with what I have to tell them.”

The quality of the stones is paramount when it comes to valuation and people are often encouraged to allow there gems to be sent for testing which can greatly increase its value.

One such example was a sapphire and diamond cluster ring. An initial estimate of £800-£1,200 was based on the likelihood that the sapphire had been heat-treated to enhance its appearance.

Upon Bonhams’ advice the customer agreed for the sapphire to be sent to a gemmological laboratory to establish the stone’s country of origin and whether it had been heat-treated.

The findings were that the sapphire was natural, of Baltic deposit, with no indications of heat treatment. It was sold for £14,375.

Leeds-born Mitchell says he was always a lover of antiques even as a small boy, spending his pocket money on pieces he loved.

“I had a particular interest in silver and I used to buy bits, and I always knew that I wanted to work in the antiques business.”

Rather than going to university like many of his colleagues and contemporaries, Mitchell left school and went straight to work for Phillips auctioneers who had just opened an office in Leeds. “My father said ‘they are bound to want a trainee’ and he was right. I was very lucky, there aren’t that many jobs at that level, particularly outside of London.”

He started from the bottom, portering and setting up sales, while learning more and more about the business from experts, but also by handling the antiques.

When Bonhams merged with Phillips, he stayed with the new company and now has more than 40 years experience in the business at first specialising in silver but then moving into jewellery. “Jewellery and silver are very connected,” says Mitchell who has also worked for Bonhams in Geneva and New York. He is widely regarded as one of the UK’s leading regional jewellery experts.

Much of what he does is detective work.

“I had a gentleman who brought a ring in to me who had bought it in a souk while on holiday really just to get rid of the very persistent stall holder.”

The man recognised the jeweller’s name, Graff, on the ring and realised that it was worth more than her paid for it.

“He wanted to know where it had come from and so I contacted Graff who can track most of their jewellery. They found out that the ring had been bought by someone who was travelling when they lost it and it had somehow ended up on the stall in the souk. The gentleman was very honourable and returned the ring to its rightful owner.”

Now Mitchell is urging people to look through their jewellery collections just to make sure there is no hidden gem among them. “I had one lady who was determined that her jewellery box was full of costume jewellery, but among it were a pair of chandelier diamond earrings. She thought they were just paste.

“People often think that granny’s old jewellery box is full of costume jewellery but it is always worth a proper look, you never know what might be among the paste.”

If you think you might have a hidden gem, contact Bonhams Leeds on 0113 234 5755 or email [email protected]


Coloured diamonds


Colourless diamonds/white diamonds



Belle Epoque/Art Deco Jewellery

Designer jewellery e.g. from Cartier, Van Cleef & Arpels, Suzanne Belperron, Tiffany

Natural pearls

Artist jewellery