A selection of conch pearls of various sizes, shapes and hues.

The shell of a queen mollusc, from which the conch pearl origanates.

As we have seen in previous posts, the market for natural gems is rising like never before.  Untreated precious stones are reaching record prices at auction and collectors are rediscovering the charm and marvel of gemstones previously considered a little obscure.  Riding high on the crest of this wave (pun intended) is the elusive conch pearl (pronounced conk).  Thanks to the creation of a cultured pearl market in the first half of the 20th century, pearl prices suffered a slump until the beginning of this one.  The destruction of pearls’ natural habitats, consumer uncertainty at not knowing where to safely deposit money and the rise of the millionaire class in the East have all contributed to the multiple price increase of natural pearls.

Conch pearl, rose gold and diamond bee ring by Cindy Chao.

Conch pearls are in a class of their own.  They are not ‘true’ pearls as generally thought of by the general public because they are not made of layers of nacreous material like ‘real’ pearls.  They do not come from oysters, but from the queen conch mollusc, which is a large, edible sea snail.  But they are formed in the same way as pearls: a foreign body lodges itself inside a mollusc, which then secretes a hard substance around it on order to reduce the irritation.  So technically they are pearls.  With conch pearls, however, the secretion around the irritant is non-nacreous, nacre being the substance that gives traditional pearls their characteristic lustre.  However, both are composed of calcium carbonate.  Hence conchs are included in the list of organic gems.

Why are they so highly prized? Only one answer: rarity.  And they are far rarer than natural pearls.  One single pearl is found in every 12000 shells; of these, only 10% are gem quality.  Conchs cannot be harvested- they can be found in almost any part of the queen conch snail, so it is not entirely understood how they are formed.  In contrast, cultured pearls have been refined to a fine art and the irritant is always inserted into the oyster in the same place in order to produce the pearl.  Pearls are also the only gem that nature produces that requires no further human treatment- no heat enhancement, cutting or polishing.

Looking and feeling like beads of fine porcelain, the colour range of conch pearls is from brown, yellow, beige and ivory through to white and pink.  The rarest and most desirable colour by far is pink.  It has been observed that the healthier the reef where the queen mollusc is farmed the more intense the pink.  The most sought after shape is a perfect oval, although irregular, baroque specimens have been used to great effect in jewellery.  Conchs also display a gemmological feature known as chatoyancy, a flame like pattern of light within the gem caused by the fibrous nature of the material. 

It is unusual to find conch pearls larger than 2-3mm; anything over 10 carats is exceptional.  One of the most important conch pearl jewels in existence is a necklace created by Tiffany and Co. in 1905 for the American art collector and philanthropist for his niece Laura Delano.  It is a typical Belle Epoque necklace, a chain of diamonds suspending a diamond cage, inside which a 23.50 carat pink conch pearl sits.  The necklace is extremely valuable: exceptional pearls of this size and value can easily reach $15000 a carat.  If you are prepared to compromise on quality, you should still be prepared to shell out in the region of $5000.

An exceptional conch pearl and diamond ring by David Morris.  If you look closely you can see the flames on the surface of the stone.

Diamond, conch pearl and coloured gem earrings by Anna Hu.

Conch pearls have risen in popularity recently in line with natural pearls.  They are particularly treasured and sought after in Japan after a huge push by Mikimoto (the Japanese cultured pearl pioneers) to educate the public on them.  In the United Kingdom, they are a particular favourite at David Morris, where they have been used to great effect.  They also seem to be particularly popular amongst artist jewellers such as Sarah Ho, Anna Hu and Wallace Chan, all of whom specialise in creating spectacular, one off jewels.  To which this most rare of gems lends itself perfectly.

A conch pearl of great importance, a 23.50 carat specimen in a necklace made for the philanthropist Henry Walters by Tiffany and Co. in 1905.


The pearl and diamond Lover's Knot tiara, made by Queen Mary and passed down to her descendants.

The Lover’s Knot tiara was one of Princess Diana’s favourite pieces of jewellery, probably the piece that most people can recall when they think of her.  It was probably presented to her by the Queen on her marriage to the Prince of Wales in 1981 and it is good to see that it has been put to further use by her successor, the Duchess of Cambridge.  It is an elegant, balanced, stylish jewel with the sharp increase in the value of natural pearls its value today is probably almost incalculable, containing as it does the set of perfectly matched natural drop shape pearls.  Spectacular and rare it may be, but it is not a unique jewel.

Princess Diana wearing the tiara with panache: teaming it up with a pearl bolero jacket.

Queen Mary wearing the tiara given to her by the Ladies of Great Britain as a wedding present.  She removed the upright pearls to create the Lover's Knot tiara.

The original Lover’s Knot tiara, made in around 1818, was a jewel owned by Augusta, Grand Duchess of Mecklenburg Strelitz, aunt and godmother of Queen Mary (grandmother of the present Queen).  It was a piece that Queen Mary knew well and which she much admired.  She did not inherit it, however- probably on the grounds that Queen Mary already had a lot of jewels at her disposal and would have access to even more on her accession to the British throne.  The tiara was left to the Grand Duchess’ granddaughter.

The tiara known to us was ordered by Queen Mary from Garrard and Co., then Crown Jewellers, in about 1913.  This was less than three years after hers and her husband’s accession and amongst other things, was busy remodelling several pieces to suit her own taste.  She created an exact replica of the Mecklenburg tiara; the original also contains upright pearl drops in addition to the ones suspended in the frame, which Queen Mary also copied.  For these, she removed upright pearls from the Girls of Great Britain and Ireland tiara which she had been given for her wedding and set them on her new Lover’s Knot tiara.  The drops were then made detachable and permanently removed in 1932.  It was in this form in which the Queen inherited the piece on Queen Mary’s death in 1953.

The Queen presented the Lover’s Knot tiara to Princess Diana on her marriage to the Prince of Wales in 1981.  It matched her personality perfectly- romantic bows, diamonds to complement her skin tone and pearls representing innocence.  As she evolved as a fashion figure, she was able to incorporate the tiara into some of her more daring outfits with panache- it could be argued that the tiara and the Princess made each other iconic.  It is now worn by the Duchess of Cambridge.

Princess Tatiana Youssoupov wearing her Lover's Knot tiara in a portrait by Winerhalter.

A Bolshevik committee evaluating Tsarist treasure.  The Youssoupov tiara can be seen at the bottom left hand corner.

There were other copies of the Lover’s Knot tiara in other princely European families, notably those of Saxony and Bavaria.  These have not been seen decades and are unlikely to have survived.  There is a loss that must be mourned, however, and this is of the Youssoupov Lover’s Knot tiara.  Contemporary photographs of it show it containing large, perfectly matched natural drop pearls, the shape and size being superior to those in the British version.  As this was made for the Youssoupovs, the richest family in Tsarist Russia, we can assume the quality was impeccable, too.  From a gemmological point of view it is sad that this fine assemblage of perfect pearls was dismantled.  The tiara was last seen on the table of the Bolshevik committee tasked with valuing and selling Tsarist treasure.

The original, however, the 1818 tiara that probably sparked all those copies, is still around and remarkably, intact.  It was auctioned by Christie’s in 1981 with the buyers rumoured to be a noble, rich, German family. 

The original Lover's Knot tiara, from which Queen Mary copied hers: note the upright pearls on top of the piece.


A publicity photograph of the Grand Mazarin diamond, due to be auctioned by Christie's Geneva next month.

It seems ironic that having written extensively about the French Crown Jewels only a few weeks ago, one of the most spectacular stones from that collection should suddenly appear at auction.  The gem in question is called the Grand Mazarin, a 19.02 carat of very pale pink colour originating from the fabled Indian mines of the Golconda, known for producing diamonds of exceptional clarity.  It is the same mine that produced beauties such as the Koh-i-Noor and Regent diamonds.

The Grand Mazarin was the largest of a matchless collection assembled by Cardinal Jules Raymond Mazarin, Duc de Nevers, Louis XIV’s immensely capable first minister and successor to Cardinal Richelieu as the Sun King’s first minister.  Cardinal Mazarin was a lover and collector of beautiful things and in a privileged position to have cream of the crop.  He put together a marvellous collection of 18 diamonds which came to be known as the Mazarins, of which the Grand Mazarin was the largest.

Cardinal Mazarin, who assembled a fabled collection of diamonds and bequeathed them to the French Crown.

Upon his death, the collection was bequeathed to Louis XIV, who in turn bestowed them on the Crown.  The Grand Mazarin was a personal favourite, often worn on a chain of graduated diamonds.  The Mazarins passed through descent to Louis XIV’s successors.  A disastrous theft in 1792 in the middle of the chaos of the French Revolution saw the collection disappear and scattered to the four winds.  Some of the gems from the theft were recovered, but of the 18 Mazarins, only the Grand Mazarin came back.

The stone was set and reset into various jewels during the Empire, Restoration and Second Empire, as each monarch tried to shape the Crown Jewels to the taste of the day.  With the collapse of the Second Empire in 1870 and a Second Bourbon Restoration being comprehensively bungled by the head of that family, the Crown Jewels were sold off in 1884, the Grand Mazarin passed into private hands.  The sale is being handled by Christie’s Geneva and is the first time the stone has appeared at auction since its sale in 1884.  Experts say that the stone should fetch $9-10 million and after a lacklustre season in jewellery auctions after a record breaking couple of years, the auction houses need a sparkling headline.

It is possible that the French Government may buy it back, as it has been doing with other Crown Jewels that have appeared on the market over the last few years.  I have mixed views on this- I always find it rather sad when a famous stone gets bought and locked up forever, never worn or enjoyed.  On the plus side, if it were to join its counterparts at the Galerie d’Apolon in the Louvre, us lesser mortals would have a chance to gaze, if just for a few minutes, into the facets of history.

A contemporary photograph of the French Crown Jewels before they were auctioned by the French Government in 1884.


A star ruby, star sapphire, diamond and pearl cross by Luis Miguel Howard.  Note the difference in colour in the star rubies and sapphires.

A valuable ring set with impeccable star rubies and sapphires.

I have always been fascinated by and drawn to more unusual stones; star rubies and sapphires have an ethereal beauty to them and I have always considered them rather underrated.  Their allure is not immediately obvious as the star is not immediately obvious if viewed in natural daylight.  But shine a light on it and a crisp, white, iridescent star will appear to reveal itself from within the depths of the stone.  For me, it was love at first sight.

In this gemstone, it is a case of perfection born from imperfections.  Rubies and sapphires are the same stone- the corundum family.  The only difference between them is that when the presence of chromium is strong enough it to be red and therefore classes as a ruby.  Any other coloured corundum is a coloured sapphire.  Most rubies and sapphires contain naturally occurring flaws called rutiles- microscopic, needle like flaws which are known as silk.  A star is produced when the stone contains an abundance of silk, all criss-crossing within the stone which causes the light to diffuse and produce a six ray star effect.  This effect in gemmology is known as asterism.

A top quality star gem should be a rich, saturated colour with little or no secondary hues or overtones.  High transparency, so highly prized in conventional stones, will only result in a poor star, so good star rubies and sapphires will always be semi opaque.  The star should be crisp and almost luminous, with the rays being perfectly straight.  Star rubies and sapphires are always cut cabochon, the only way to release the optical effect within.  The star should also always be visible when exposed to any kind of artificial light- if you have to hold the stone this way and that to appreciate it, it is not good enough.  The stone should also be clean- there should be no black spots or any other visible inclusions of any kind.  With no criss-crossing facets to hide inclusions under, clean stones are rarer and therefore more expensive.

A diamond ring set with a grey star sapphire.  This colour is more affordable and still makes it an attractive, desirable gemstone.

A star ruby and diamond necklace sold at Christie's.  This stone weighs 250 carats and fetched $190,000 at auction.

The highest quality gems come from Burma for rubies and Sri Lanka for sapphires.  That said, the largest star ruby in the world, the 138 carat Rosser Reeves in the Smithsonian is Sri Lankan.  Demand for perfect rubies and sapphires has soared (especially in Asia) and fewer gems of larger sizes (five carats and above) are being mined.  This has put enormous pressure on wholesalers to satisfy the market- most star rubies and sapphires of exceptional quality will be heat treated (this is not uncommon: 90% of the world’s coloured gems are heat treated) to dissolve the silk and produce the coveted faceted gemstones which are achieving world record prices at the moment.  As such, perfect star rubies and sapphires are extremely rare- especially rubies (which are already the world’s rarest gemstone), where you can expect to pay $50000 a carat for a perfect example.  A perfect blue is not so rare, but you can still expect to part with over $5000 a carat if the stone is over 5 carats.

However, if on a budget (as most of us are) one can easily compromise on the colour- and sometimes I find that ‘less than perfect’ stones will suit a jewel or a wearer almost better than the textbook example.  There are beautiful examples to be found in greys, soft blues and pink for a tenth of the price quoted above- if you are thinking of buying one, just don’t compromise on the star- after all, that is the point of a star gem.  Above all, choose a stone that speaks to you.


Salon de Mercure bracelet by Dior in rubies and diamonds.

Marqueterie cuff bracelet by Boucheron in chalcedony, mother-of-pearl and diamonds.

There is no doubt about it, big bracelets are back: in these days of so-called austerity, more is more.  For some years now, jewellery has been mirroring the way we shop: the acquisition of one or two very good life lasting pieces to be mixed in with fun high street buys.  More than one fashion editor is to be seen on social media sporting an armful of pretty bracelets, Dior gold and diamonds stacked up with colourful holiday buys.  The days of wearing a single golden filet on a delicately bronzed wrist have been replaced, in these days of so-called austerity, by the look of ‘more is more’.

In the world of fine jewellery, this has resulted in the creation of spectacular statement bracelets- the elegant, restrained single line of diamonds is now supplanted by fantastical cuffs or strings of impeccably matched beads with beautiful gem set clasps.  In terms of fine and high jewellery, although some of these pieces may cost the equivalent of a deposit on a flat in Kensington, they are far easier to wear.  They transition from day to night seamlessly; a multicolour creation discreetly embellished with diamonds will look just as good with jeans and a Zara jacket as with a designer Little Black Dress.  The same cannot be said for a diamond necklace or oversized chandelier earrings.

My Green Cuff, by Chanel, in diamonds, tourmaline and malachite.

Of course, large bracelets are nothing new- they have been an almost indispensable classic since Chanel teamed up with Verdura to create their famous cuffs.  Today, one of their strongest designs is a piece called My Green Cuff, a strong structural design in malachite and tourmalines which evoques marquetry techniques.  Speaking of marquetry, Boucheron have just launched a range precisely on that premise- their Marqueterie collection is a harmonious blend of greys and blues in chalcedony, mother of pearl and diamonds.  The clean, geometric designs are a refreshing move from the jewelled bouquets and menageries of other jewellers.  The cuff is genius, covered in small triangular stones which have all been precision cut to fit in with each other. 

Over at Dior, Victoire de Castellane offers a more neo-baroque approach with her Dior at Versailles collection, her irreverent juxtaposition of colour continuing to dominate the pieces.  On the British front, Theo Fennell’s solid gold Palm bracelet is an instant classic that should not date.

A lot of what is on offer borders on looking like costume jewellery- almost willing someone to look at the wearer and ask themselves ‘Is that really a £50,000 she’s wearing to lunch?’. It is a whimsical quality which I find fun and highly attractive in fine jewellery. 

The Cuff Queen: Coco Chanel photographed in the ritz wearing her trademark pearls and Verdura cuffs.


The engraved eternity band given to Vivien Leigh by Laurence Olivier, nestling among two important bow brooches.  The brooch on the left is the most valuable item in the sale, estimated to fetch £35,000-£40,000.