The Siren of Serendip

A superlative blue sapphire lies at the heart of this story and that is where we begin our narrative. This is absolutely fitting given that precious gems are the vital inspiration behind every piece of jewellery that emanates from Henn of London’s studio and workshop.

Following the acquisition of an exceptional sapphire known as the Siren of Serendip in 2018, the Houston Museum of Natural Science (HMNS) commissioned Henn of London to create a very special necklace to showcase this extraordinary gemstone.

The original rough crystal was discovered in Sri Lanka, formerly Ceylon, almost a century ago and weighed an astonishing 2,670 carats prior to being cut and polished. The majestic 422.66 carat blue sapphire that emerged has been described as a world class stone.

Richard W Hughes, the renowned gemmologist, expert and author who delivered a lecture relating to rubies and sapphires at the HMNS in March 2019, had this to say about the gem: “… not only is it exceptionally well cut for a stone of this size, but the colour is also exceptional and it’s certainly in the top 5 sapphires I’ve ever seen in my life of this kind of size… This is an exceptional piece… You’re very, very lucky to have something like this in the collection.”

The Siren of Serendip’s name is laced in legend and also “serves as a nod to the serendipity the museum feels at having the opportunity to own this stunning piece”, according to the HMNS whilst, “The term Siren is a reference from Greek mythology to irresistible – yet unattainable – beauty that captivates those who behold it; Serendip is the ancient Persian name for Ceylon, used since antiquity to describe this rocky ‘island of gemstones’.”

The word ‘serendipity’ was coined in 1754 by Horace Walpole, a pivotal figure in 18th century British society, literature, art and architecture, founder of Strawberry Hill House in Twickenham with its vast collection of treasures. He is widely recognised as the most important English collector of his time. The expression was inspired by, quoting Walpole, “a silly 13th century fairy tale” called The Three Princes of Serendip, in which the key protagonists “were always making discoveries, by accidents and sagacity, of things they were not in quest of”. There seems no doubt that Walpole would have approved of the Siren of Serendip and its necklace.



Gemstone Heritage

Henn of London’s association with the HMNS began in the heart of the gemstone trade in the US, at the Tucson Gem and Mineral Show some 40 years ago. Hans-Jürgen Henn, father to Ingo Henn of Henn of London and creative director of Henn, the historic family gemstone business, had been involved with the Tucson exhibition since its inception. The show’s unique blend of general public and enthusiastic collectors with experts and professionals in gemmology and mineralogy had from the outset established its reputation as one of the most popular and prestigious gem events in the world, which remains true to this day. “I started going in the early Seventies and it is still one of my favourite exhibitions. It was one of the first in the business and it continues to generate the same excitement all these years later. It was in the late 70s that I first met Joel Bartsch there, a bright young lad who was very enthusiastic about gemstones.  We kept in touch over the years, meeting up every so often, connected by the same passion and fascination for minerals and rare precious stones.”

Joel went on to study mining engineering. Further academic studies and his subsequent career eventually led him to becoming the Curator of the Cullen Hall of Gems and Minerals at the HMNS. He was also responsible for a number of the museum’s temporary exhibitions and permanent show spaces, including the renowned Wiess Energy Hall. Highly respected in the field of mineralogy, he was appointed President and CEO in 2004 and in this role has continued to curate major sections of the museum.

In 2006 Joel was instrumental in setting up a dedicated gem vault as a permanent exhibition area to complement the by then world-famous Cullen Hall. He described it thus “… the Gem Vault started out with the idea that we wanted to build on our existing collection of world class gem and mineral crystals. The idea was that we had the finest collection in the world of natural emeralds, rubies and sapphires and we thought the perfect complement to that would be a world class collection of cut and faceted and polished pieces… The thought was you have something for the geologists and we wanted to have something for the gem collectors as well, so it’s kind of a natural marriage of the two…. We want the best of the best out on display.”

The HMNS extended its interests from mineralogy and gemmology into the lapidary world and the development of what Joel termed “world class jewellery”. Gems displayed as wearable treasures considerably widened their public appeal, making them more relatable to visitors who were not professionally involved or particularly engaged with the more scientific aspects of mineralogy.

Around the time of the Gem Vault opening, which was in 2006, Joel purchased some exceptional gems for the museum from Henn. They included a stunning set of peridots. He subsequently commissioned Henn of London to create a parure to showcase these precious stones. An elegant ring and a sumptuous pair of earrings joined a signature necklace which had been the original starting point of the project. The whole set featured the 16 exquisite Henn peridots and a multitude of diamonds, all in a classically inspired ribbon and bow motif design.

Following this earlier introduction, Henn of London were approached with a further jewellery commission in 2018. There was a degree of secrecy attached to the first meeting due to the importance and rarity of the gemstone involved. It was the Siren of Serendip, which had not yet been shown in public. Joel was looking for an inspired way in which to present it. He was keen to emphasise the sheer beauty of this exceptionally important stone as the centrepiece in a jewel rather than displaying it unmounted.

An initial design meeting took place in London in April with Ingo Henn, Jürgen, Joel and Stephen Sachnik from the HMNS. The brief was for a simple, elegant and classically inspired yet contemporary design, which might somehow incorporate a reference to Texas – a necklace that would complement the strength and grace of its principal stone and allow its undeniably powerful presence to shine centre stage.



Designing the Necklace

The Henn of London design team, namely master goldsmith and jeweller Ingo, and Jennifer Bloy, another highly talented jewellery designer, explored some initial ideas that would appeal to the client whilst resonating with the studio’s house style and aesthetic.

Inspirational research led to the ‘bluebonnets’, a family of vividly coloured lupins (Lupinus Polyphyllus) which grow wild across the local American prairies. As well as their striking colour, their petals are reminiscent of the shape of early pioneer women’s bonnets, hence their name. They are also the state flower of Texas and thus felt like a natural choice within the necklace’s ornamental detailing.

A highly stylised abstraction of a lupin flower was woven into the composition. A selection of visual concepts was then translated into sketches which were presented to the HMNS in June.

The clients’ favoured design was chosen and developed into a jewel which blended this almost subliminal Texan reference with an elegant art deco aesthetic that chimed with the cut of the stone, together with a subtle contemporary twist – suffused classic modernity being the very essence of Henn of London’s creative style. With rare gems as the primary focus in all their projects, the team is well versed in working synergistically with the colours, shapes and other inherent qualities that each precious stone presents.

Stephen returned to London for a few days in August to make some final sensitive adjustments to fully reflect Joel’s original brief, working with Ingo and Jennifer to refine the composition and ensure that the necklace’s dynamic statement was in complete harmony with the exceptional beauty of the Siren of Serendip.

The jewel had evolved into a necklace that breathed grace and style from the tip of the diamond which was delicately balanced from its clasp to the deep blue epicentre of the wondrous sapphire at its heart. The production process was now in full swing.

The Making of the Necklace

Owing to the extraordinarily high value of the Siren of Serendip, a perfectly proportioned replica was sent to Henn of London from Texas in early autumn. The original was far too valuable to travel and then reside in the company’s workshops for the length of time needed to design and make the intricate necklace. It was agreed that Ingo and Ian Read, the team’s expert gemstone setter, would fly out to Houston as and when the real sapphire was required to perfect and then complete the setting.

With some 20 years of successful projects in their repertoire, Henn of London’s synergistic approach had always encompassed working with an extended team of brilliant craftspeople to create masterpieces. With the Siren of Serendip this included the talented and accomplished jewellery maker Jan Philips; goldsmith Tim Liley and Ian, both highly respected in their fields; as well as John Oldland, one of London’s top jewellery polishers.

The team collectively considered the practical challenges involved in working with a gemstone of this size, weight and scale. This included an early decision to combine 18 carat white gold for the main body of the work with platinum claws to support and enhance the valuable sapphire at the heart of the necklace.

By October the team were fully immersed in both the functionality and the aesthetics of the design, embracing the volume, depth and height of the sapphire alongside its unique luminosity. They used sketches, line drawings, wax models and their collective skills and technical experience to explore a multitude of options, right down to the smallest detail. Equal focus was given to each aspect of the precious stone with the creation of a harmonious and graceful setting that would allow the extraordinary gem to be appreciated from every angle.

In January 2019, the central section of the jewel was complete and Ingo and Ian travelled to Houston. Their aim was to temporarily pre-set the Siren of Serendip into its precious new white gold and platinum setting to ensure its ultimate immaculate fit. Even though a workbench had been specially installed at the museum, Ian took his own tools, leaving nothing to chance. Ingo concentrated on the visual elements of the piece and the integrity of the design, given that he would normally have had a jewel’s main gemstone present in the studio as a constant reference.

With the setting perfected, the team were reunited back in London where work on the rest of the necklace continued. Each of the links was created along with an elegant clasp which would provide a counterpoint to the central sapphire.

Every single detail was carefully considered, “putting real soul into the piece” as Jan so aptly described the process – each tapered link including its scale and distance from the next reflecting an overall sense of refinement and ensuring the dynamic flow of this unique world-class necklace.

The handpicked diamonds, 913 of them in total, with a collective weight of 36.30 carats across the whole piece, were expertly set to enhance the luminescence of the Siren of Serendip, their glowing white translucence contrasting and offsetting the deep blue hue of the central sapphire.

As is often the case with high end jewels, much of the necklace was designed with galleried sections and ‘ajouré’ settings to create a sense of radiance and refinement, whilst adding luminosity across the whole piece. The French term ‘ajouré’ describes the design process, rather like filigree in appearance, which leaves defined open spaces in the worked metal. However, unlike filigree, these detailed sections tend to be cut out of the metal rather than being included in the construction. This approach is reminiscent of a particular style of French lace known as ‘ajour’, ‘à jour’ meaning ‘in daylight’, thus the terminology.

This sensitive and delicately detailed consideration for the radiance of the piece’s gems, its graceful lines and the fine-tuned intervals that defined each element all pointed to the heart of the composition. Here a pre-eminent 4.02 carat pear shape diamond was chosen to draw poetic attention to the Siren of Serendip sapphire, set amidst other perfectly placed and prominent pear shape and marquise diamonds. The elegant simplicity of the catch design at the nape of the neck featured the second most important diamond, creating a harmoniously balanced counter note to the stunning centrepiece.

The symphony was almost complete. As the necklace neared the final stages of the production process, the piece was signed with its maker’s name, ‘Henn of London’, beautifully hand engraved inside the back of the centre section. The jewel was later taken to the Assay Office where Henn of London’s official British hallmark was placed on the back sheet of the clasp, signing the whole design with its maker’s identity for posterity.

As the end of February approached, Ingo and Ian flew to Houston a second time for the last stage. Having first been polished and rhodium plated by John, the necklace had been carefully wrapped to protect it from scratches and other damage. Once the nerve-wracking process of setting the pièce de résistance was over and with the spectacular Siren of Serendip now resplendent at the heart of its new necklace, the making process was complete. It was time for Ingo to remove the protective tapes. This final step took several hours to carry out, prior to a delicate polish of the platinum claws in preparation for the handover.



A Perfect Setting

Ten months had elapsed since the original commission and Ingo was now ready to present Henn of London’s masterpiece to the museum. It was the 24th February and HMNS staff were the first to behold and handle the sumptuous finished necklace prior to its grand début in the museum’s Brown Gallery, where it was to be on show for 3 weeks.

A special stand had been designed to elevate the Siren of Serendip jewel into a position from which it could be admired in its full glory from every angle, as if it was floating in the air.

In the first week of March, a grand reception and dinner attended by top-level donors, press and local celebrities as well as key museum staff and fundraisers offered a perfect opportunity for the official unveiling.

Following the initial exhibition, the Siren of Serendip jewel was moved to a permanent display area in the HMNS Gem Vault towards the end of March 2019. This entire journey had been made possible thanks to “… a little serendipity, and a large amount of generosity from multiple anonymous donors.”

What makes this necklace so very special? The glorious sapphire at its heart naturally, or as Ingo put it so well: “Every stone is different and has its own character and personality. A gemstone such as the Siren of Serendip has a huge presence and that presence will touch and inspire many, through generations to come. I would like to think that this piece will resonate with younger people especially and that it might spark future passions – for superlative gems or superlative jewellery design or a combination of both.”

The Siren of Serendip sapphire is already legendary. Illuminated by diamonds, harmoniously poised at the heart of Henn of London’s bespoke necklace, its flawless poetry is a vision to behold, a natural gift that transcends time. Borne from the depths of an ancient earth, transformed into a captivating jewel, the Siren of Serendip is now forever on show, for all to admire, in one of the US’ most forward thinking natural science museums.