My new article in Jewellery History Today, the magazine of the Society of Jewellery Historians, shows the relationships between Martin Coster – founder of Royal Coster Diamonds –, Oscar Massin and King William III of the Netherlands. This historical research and visual comparison serve as basis for the attribution to Massin of the pendant, bow brooch and necklace of the diamond and sapphire parure of the Dutch Royal House. Massin himself provided evidence of Martin Coster’s role as liaison between him and King William III. He wrote about the engraved diamond portrait medallion he made, confirming it was a gift from Coster to the King, to give to his bride Princess Emma of Waldeck-Pyrmont.
The article here is an expanded and corrected version of the article in Jewellery History Today.
Oscar Massin is arguably one of the greatest jewellers to have the least recognised body of work. He was not accustomed to signing most of his pieces because his work was largely sold through other Parisian jewellers. Even less well known is the fact that the Royal House of the Netherlands owns several of his designs, and new research shows that there are likely even more Massin jewels in their collection.
Mellerio and Massin are the only Parisian jewellers known to have supplied King William III of the Netherlands. In his book Mellerio dits Meller, Joaillier des Reines, Vincent Meylan confirms that the original designs for an imposing diamond and Burmese ruby parure provided by Mellerio are Massin’s work, and it is also possible that he made it. William III gave this parure to his young Queen, born Princess Emma of Waldeck and Pyrmont, at Christmas in 1888. On the day of their wedding in Arolsen on January 7 1879, at the entrance of the church, the 61 year old King gave his 20 year old bride a medallion made by Oscar Massin with a large pale yellow diamond with the King’s portrait engraved in it. Princess Emma pinned the medallion immediately on her wedding dress.
One of Massin’s greatest designs is visible in the diamond and sapphire tiara of the Dutch Royal House. While it is clearly based on an all-diamond tiara shown by Massin at the Paris Exposition Universelle of 1867, the Amsterdam-based broker of diamonds, pearls, and artefacts Vita Israel supplied it. They delivered this tiara and two accompanying bracelets on 14 December 1881. For their engagement on 29 September 1878 the King had already given Emma a diamond and sapphire pendant and bow brooch, featuring a very large sapphire inherited from his mother Queen Anna Pavlovna, born Grand Duchess of Russia. And at some point between then and December 1881, a dog collar was added.
While the maker of these three jewels is unknown, they are confirmed as being of French manufacture. Many assumed the jewels were provided by Mellerio, which was emphatically denied by Meylan, who stated the House’s archives do not contain any reference to these jewels. In this article I lay out the probability of Oscar Massin being the logical choice for maker of these jewels. And why were the tiara – a near copy of Massin’s 1867 briolette diamond tiara – and bracelets ordered and made in the Netherlands? And who was the link between Oscar Massin and William III?
Massin and Coster in 1867
The Paris Exposition Universelle of 1867 launched Massin on the international stage. While his studio was already swamped in work for several Parisian jewellers and their presentations at the Exhibition, Joseph Halphen – the most prominent and possibly only diamond provider in Paris – suggested to Massin, six weeks before the opening, that Massin exhibit under his own name. Halphen promised to provide Massin with all diamonds and, to minimise risk, offered to buy the newly produced stock in advance. Massin triumphed, one of the highlights being the briolette diamond tiara, of which the Dutch sapphire and diamond tiara is almost an exact copy.
At this point, the link with the Netherlands comes in. In the 1860s, Halphen was so successful that he outsourced the processes of diamond sorting and cutting to Coster, who had just set up a branch in Paris. Coster’s workshop in Amsterdam was renowned for cutting the Koh-i-Noor and the Star of the South diamonds, both shown at the 1855 Exhibition. Halphen added considerably to Coster’s success by outsourcing the whole diamond sorting and cutting process to him, which made him immensely rich.
Coster had his own triumph at the 1867 Exhibition by setting up a diamond-cutting factory – a smaller copy of his Amsterdam factory at the Champs de Mars – to demonstrate the entire diamond production process, which was much talked about and appreciated by the public and in the international press. Massin and Coster also collaborated at this point, because one of Massin’s exhibited jewels was a collar pendant in Louis XIV style, made for Coster using his diamonds. The collar pendant contained extremely rare diamonds: a blue brilliant of 30 grains, a vivid red brilliant (1,5 grain), a white briolette (28.5 grains) and a white brilliant of 8 grains of superior quality.
Coster and the King
Martin Coster was member of the Dutch organizing committee for the 1867 Exhibition, specifically the subcommittee for precious stones and other precious items. His own participation with the diamond factory at the Champs de Mars earned him a gold and silver medal, and a Knighthood in the Legion d’Honneur by Napoléon III, a personal friend of King William III. In 1868 Coster was appointed by King William III as Consul General of the Netherlands in Paris and as Knight in the Order of the Netherlands Lion.
In February 1872 the King made Coster Commander in the Order of the Oak Crown, possibly because of his role during the revolution of the French Commune in 1871. Instead of fleeing the city, Coster remained in Paris so he could play his diplomatic role. The plans in December that year of President Thiers to tax rough diamond, which would hit the Amsterdam diamond industry hard, were prevented because of Coster’s intervention.
Another option is viable as well: King William used the Oak Crown as his personal order, which he could bestow without permission from the government. Both him and his son, the Prince of Orange, preferred the many mundane attractions of Paris to the Netherlands. The Prince – who was by no means attracted to state business or succeeding to the throne – even permanently moved there, where he was known as Prince Citron and ran up millions of Francs in debt. Similarly the King spent a lot of time and money in Paris, so it is thinkable that Martin Coster as Consul General was involved in many aspects of the King’s private life for which he expressed gratitude. The first recorded contact between Coster and the King was his visit to the factory in Amsterdam in 1862, together with the Crown Prince, the Prince of Orange. Coster also knew King William’s first wife, Queen Sophia, as is confirmed by her visit to the 1867 Exhibition, where Coster was one of her guides, and a private audience granted to Coster in 1877.
Massin in Amsterdam
In 1877 an international exhibition was organized in Amsterdam. The King’s sons – the Prince of Orange and Prince Alexander, President of the Organizing Committee – were fundamental in finding the funding for this venture and the King was also involved, as was Martin Coster, as member of the organizing committee. Oscar Massin was one of the exhibitors at the exhibition, for which he won a second prize.
1877 is also the year in which King William’s private life unravelled. The King, a lover of the arts, had started an affair with the Parisian opera singer Emilie Ambre, famous for her role as Carmen in Bizet’s opera. Edouard Manet made a portrait of her in that role. The King, recently widowed after a disastrous marriage, had set his mind upon marrying her, even if it meant abdicating his throne and moving to Paris. This would cause serious problems: the only male members of the House of Orange that were left were either unwilling to succeed the throne, unlikely to ever marry, or too old to provide another heir who could continue the Dutch monarchy.
There was no other choice that the King would have to remarry, which would prove to be hard because his reputation in Europe – due to his often-erratic behaviour – was dismal. He even tried to sell his Grand Duchy of Luxembourg to Napoléon III in order to settle his debts. But he knew what he had to do: in 1878 he set upon a European tour to find himself a new Queen. 
The 1878 Exhibition
While the King was searching for his bride, the Paris Universal Exhibition of 1878 happened. Martin Coster, as Delegated Commissioner, was the lead in the Dutch participation, while the King’s brother Prince Henry was honorary chairman of the Dutch organizing committee. Coster invested large amounts of his own money in the Dutch pavilion. Although it was reported that Martin Coster would make his villa in Paris available to the King, this was incorrect. The King installed himself in another villa in the Rue de Rome bought especially for the Exhibition. Large amounts of furniture and art were moved from the King’s main residence Palace Het Loo to Paris for the exhibition.
One of the exhibits in the Dutch pavilion was the silver gilt cup in gothic style – made by the Leeuwarden goldsmith Keikes – which King William had given to Martin Coster. Coster added to the international prestige of Holland by organizing Dutch horse races in the Bois de Boulogne. The 2-day event was a huge spectacle at which general Mac-Mahon and many other dignitaries were present. It was reported that Coster invested 60.000 Francs of his own money in this project. Free champagne and cigars were provided for everyone, including, according to one news report, the King’s son the Prince of Orange. Shortly after the races, a French newspaper reported that the King had bestowed upon Martin Coster the title of Count, although no record of this ennoblement is available and Coster never used the title. But the French Republic promoted Martin Coster to Commander in the Legion of Honour for his work for the 1878 Exhibition, while in 1879 King William III also bestowed upon Coster the Commander in the Golden Lion of Nassau and promoted him to Commander of the Order of the Netherlands Lion. This happened shortly after the death of the Prince of Orange in Paris. Coster was present at all parts of the mourning ceremonies in Paris and was present at the transport of the Prince’s body to the Netherlands for his burial.
Coster won a silver medal for his participation in the 1878 exhibition, although under a different name, that of Alexander Daniels. He was the Director of the Amsterdam diamond factory owned by Martin Coster, but operated under Daniels’ name. One of the marvels of Daniels’ exhibit was the diamond with King William III’s portrait engraved in it. The seemingly impossible engraving was done by the Amsterdam engraver and medallist M.C. de Vries, it reportedly took him 5 years to finish the job. De Vries also engraved Napoléon III’s portrait that was exhibited in Coster’s factory at the 1867 Exhibition.
Massin’s work in 1878
Although photographic evidence is lacking, literature confirms that once again Oscar Massin presented the briolette tiara and the Louis XIV neck pendant owned by Coster at the 1878 Exhibition , indicating that Massin considered these highpoints in his own work.
Massin was awarded the Grand Prix by the Jury and the Legion of Honour for his display. It included two jewels that are of particular relevance to the pendant and necklace in the Dutch Royal Collection.
One is the diamond belt bought by the Nizam of Hyderabad, the central element of which shows a remarkable resemblance to the pendant. The other one is the diamond tiara that was bought by the Duke of Fife for his bride Princess Louise of Wales, which is known as the Fife tiara and was recently acquired by the Government of the United Kingdom.
Its design principles are similar to the briolette tiara, the Dutch sapphire tiara and the Dutch sapphire necklace. Vever mentions that around 1870 Massin started to produce necklaces with elaborate borders containing trefoils, just like the necklace. When looking at the bow brooch with the giant sapphire – a heirloom of King William’s mother Grand Duchess Anna Pavlovna of Russia – it is interesting to note that the ends of the ribbons are split, characteristic of the available designs for bow brooches by Massin.
Coster’s present to the King
While the Exhibition was happening in Paris, the King found his bride in the minor German Principality of Waldeck and Pyrmont, where he spent much time in the fall of 1878. The 20-years old Princess Emma was one of three sisters available and the only one willing to marry the King to prevent the House of Orange from going extinct. Apart from the bow brooch and pendant the King gave as engagement presents, he presented Emma with the medallion made by Oscar Massin containing the engraved diamond portrait of the King.
In his 1889 Paris International Exposition report, Oscar Massin wrote: ‘I knew, because I had mounted them in 1867 and 1878, diamond-portraits, intaglio engraved [..] One depicted Napoléon III, the other William, King of the Netherlands, who currently reigns. This latter engraved diamond, much more superior to the first in matter and in art of engraving, was mounted in a medallion [..] surmounted by the Dutch royal crown and offered to the King with respect by Mr Coster, his Consul General in Paris, during the wedding of his Majesty to the young Princess of Pyrmont-Waldeck’ [sic].
Thanks to Oscar Massin himself we know that Martin Coster acknowledged his special relationship to the King with this thoughtful gift.
Thoughtful, since the medallion is completely set with rose diamonds, a cut that was best known as ‘Dutch rose-cut’. The magnificent gift confirms the close relationship between the King and his Consul General in Paris who triumphed together at the Exhibition of 1878 in Paris, raising the profile of the Netherlands on the international stage. Consequentially, this was also the meaning of the gift of this medallion by the King to Queen Emma. Romance was not part of this alliance.
A new phase
So why did the King not order the tiara and the bracelets of the parure from Massin as well? Why not allow him to finish the magnificent set? After his wedding, the King lost focus on Paris and instead enjoyed family life: in August 1880 his daughter Wilhelmina was born, the last hope for continuing the dynasty, whose descendants still reign. In January newspapers reported that Martin Coster fell seriously ill, while on January 31st it was reported that the King had promoted Martin Coster to Commander in the Order of the Netherlands Lion. Martin Coster died on February 1st. As one newspaper wrote: ‘Holland lost its most popular Consul [..] It was generally known how Mr. Coster was a Consul who could only be desired, always ready to defend, with his person and his great wealth, the interests of his country and countrymen, and raise the honour of the fatherland.’ It is interesting to note that the Dutch government decided to not find a new Consul General, a confirmation of the theory that Coster and the King had a close relationship, while the King – from the moment of his marriage to Queen Emma – had no desire for a personal liaison in Paris anymore. In April 1880 the King officially disbanded the Consulate General that was separate from the Dutch Embassy, and appointed a Consul from within the organization.
Martin Coster was buried in the Jewish section of Montmartre, and in May that year the sale of his considerable art and antiques collection at his hôtel at Avenue Marceau raised over 500.000 francs.
 Erik Schoonhoven, A very Parisian Affair: Oscar Massin’s Jewels in the Dutch Royal Collection, in: Jewellery History Today, the magazine of the Society of Jewellery Historians, issue 31, Winter 2018, pp. 6-7.
 Emerentia van Heuven- van Nes, Emma, Koningin der Nederlanden, Prinzessin zu Waldeck und Pyrmont 1858-1934, Museum Bad Arolsen, 2008, p. 27.
 Jules Mesnard, Les Merveilles de l’Exposition Universelle de 1867, Impr. De Lahure, Paris, 1867, p. 129.
 René Brus, De juwelen van het Huis Oranje-Nassau, Uitgever Schuyt & Co, 1996, pp. 71-74.
 Henri Vever, translated by Katherine Purcell, French Jewelry of the Nineteenth Century, Thames & Hudson, 2001, pp. 712-716.
 Idem, pp. 576-577.
 Pierre Aymar-Bression, Histoire générale de l’Exposition universelle de 1867: les puissances étrangères, Impr. J. Claye, Paris, pp. 54-56. Journal des débats politiques et littéraires, 27 juin 1867.
 Mesnard, 1867, pp. 130-132.
 Weekblad van Tilburg, 7-10-1865. Bredasche Courant, 4-2-1866.
 Nieuwe Rotterdamsche courant, 3 juli 1867. Dagblad van Zuidholland en ’s-Gravenhage, 3-7-1867.
 Middelburgsche courant, 27-10-1868.
 Algemeen Handelsblad, 10-12-1870.
 Het Nieuws van den Dag, 28-12-1871.
 Dik van der Meulen, Koning Willem III, Uitgeverij Boom, 2013, pp. 422-502.
 Algemeen Handelsblad, 27-3-1862.
 Weekblad van Tilburg, 12-10-1867. De Standaard, 17-2-1877.
 Catalogus der Tentoonstelling van Kunst Toegepast op Nijverheid, C.L. Brinkman, Amsterdam, 1877. Het Nieuws van den Dag, 13-7-1877, 17-9-1877. Algemeen Handelsblad 11-7-1877, De Standaard, 3-2-1877.
 Meulen, pp. 503-591.
 Catalogue spécial des produits exposés par le Royaume des Pays-Bas, publié par la Commission royale, Exposition Universelle de Paris en 1878, Impremerie De Giunta d’Albani Frères, La Haye, 1878.
 Het Nieuws van den Dag, 3-6-1878.
 De Standaard, 11-8-1877. Provinciale Noordbrabantsche en ’s-Hertogenbossche Courant, 3-8-1878, 18-8-1877.
 Rotterdamsch Nieuwsblad, 26-9-1878.
 Rotterdamsch Nieuwsblad, 30-9-1878, 1-10-1878, 7-10-1878, Apeldoornsche Courant, 5-10-1878.
 Le XIXe siècle, journal quotidien politique et littéraire, 8-10-1878.
 Nederlandsche Staatscourant, 30-11-1878.
 De Standaard, 17-7-1879. Het Nieuws van den Dag, 25-12-1879.
 De Standaard, 16-6-1879. Het Nieuws van den Dag, 25-6-1879.
 Catalogue spécial des produits exposés par le Royaume des Pays-Bas, publié par la Commission royale, Exposition Universelle de Paris en 1878, Impremerie De Giunta d’Albani Frères, La Haye, 1878. Nederlandsche Staatscourant, 13-12-1878.
 Diana Scarisbrick, Portrait Jewels, Thames & Hudson, 2011, pp. 346-348. Het Nieuws van den Dag, 6-6-1878. Journal des débats politiques et littéraires, 27-6-1867. Etudes sur l’Exposition de 1867, p. 339.
 L’art et l’industrie de tous les peuples à l’Exposition universelle de 1878: description illustrée des merveilles du Champ-de-Mars et du Trocadéro, par les écrivains spéciaux les plus autorisés, Exposition Universelle, Librairie Illustrée, Paris, 1878, p. 46.
 Exposition Universelle 1878, Groupe IV – Classe 39. Spécimens de Joaillerie par O. Massin. Grand Prix, Paris, 1878. Vever, p. 979.
 Arts Council England, Cultural Gifts Scheme & Acceptance in Lieu Report 2017. http://www.artscouncil.org.uk/sites/default/files/download-file/AIL-CSG%20201617%20Digital%20Annual%20Report_0.pdf
 Vever, p. 716.
 A previous version of this article stated Oscar Massin created a pearl and diamond tiara for Princess Elisabeth of Wied (better known as Carmen Sylva), given to her on occasion of her marriage to Carol I of Romania, based on this website: https://www.royal-magazin.de/romania/ella-pearl-tiara-romania.htm. From communications with the owner of the website I learned this is an attribution, which is not disclosed on the website.
 Vever, p. 702.
 MM. Jacta, Massin, Hénin et Plichon, Études et rapports techniques sur la bijouterie, la joaillerie, l’orfèvrerie et la bijouterie en or double a l’Exposition Universelle de Paris, 1889, et rapport de la Commission Administrative, Chambre Syndicale de la bijouterie, de la joaillerie, de l’orfèvrerie et des industries qui s’y rattachent, Paris, 1890, p. 76.
 Het Nieuws van den Dag, 4-2-1880. Algemeen Handelsblad, 3-2-1880. Bataviaasch handelsblad, 31-1-1880.
 De Standaard, 13-4-1880, 17-4-1880. Nederlandsche Staatscourant, 20-4-1880.
 De Standaard, 6-2-1880.
 Catalogue des tableaux anciens et modernes, objets d’art, de curiosité et d’ameublement, garnissan l’hôtel de feu M. Martin Coster, 19 mai 1880, Paris. Het Nieuws van den Dag, 26-5-1880.