Illuminating Objects: Borrowing specimens from the Oxford University Museum of Natural History

Illuminating Objects intern Natasha Gertler tells us about her research.

The art of identifying decorative stones, such as those in the Courtauld’s Baroque frame, is achieved through observation, connoisseurship and comparison with other stones of known identity, rather than scientific analysis. Composed of exactly 1000 polished stone slabs of uniform shape and size, the extensive Corsi collection was established in Rome in the first quarter of the 19th century and is now housed in the Oxford University Museum of Natural History. Most of the stones are of known provenance and hence the collection is an excellent resource for decorative stone identification.

As soon as we were introduced to the collection, we immediately contacted Monica Price, the author of the comprehensive Corsi collection website as well as the Head of Earth Collections at the Oxford University Museum of Natural History. She kindly agreed to visit the Courtauld to view the frame and her extensive knowledge of decorative stones proved to be invaluable.

What was previously thought to be a wine-coloured variety of jasper, Monica identified to be in fact most likely an inlay of the mineral amethyst backed with a red metallic foil. This became very apparent when the segment was illuminated and viewed through a microscope, producing a reddish orange glow through the translucent purple amethyst, as shown below.

Amethyst probably backed with red metallic foil

Amethyst probably backed with red metallic foil, illuminated and viewed through a microscope

From a very early stage of my Illuminating Objects internship, I decided to display the frame alongside specimens of rocks and minerals that correspond to the stones present in the frame. I wanted to do so in order to emphasise the beautiful results of the interplay of man and nature, by highlighting the stones’ transformations from rough to cut and polished, revealing the true beauty of nature’s wonders.

Having already accumulated samples of lapis lazuli and amethyst from private collections in London, Monica kindly offered to lend us a variety of Sicilian jaspers and agates from the Earth Collection of the Oxford University Museum of Natural History. Sicilian jaspers are now depleted and no longer quarried, so it is very fortunate to be able to include a selection in my display.

Enthusiastically accepting her generous invitation, I readily booked my train ticket and off to Oxford I went. The stone slabs of the Corsi collection are splendidly preserved in drawers away from public display, and remain in Corsi’s original arrangement. His arrangement is very significant as he was one of the few collectors of his time who attempted to order their collection according to the geological properties of the stones rather than superficially by aesthetic similarities.

The Corsi collection is magnificent. Almost bursting in awe, I perused the stones, locating brilliant samples of my favourite rocks and minerals whilst discovering new colours and patterns I thought only to be imaginable.

I could have continued for hours but work had to be done. Monica kindly showed me the agates and Sicilian jaspers from the Earth Collection that I could choose to borrow. Having made my selection with Monica’s helpful guidance, and filled out the necessary paperwork, I returned back to the Courtauld Gallery with the specimens under my fierce protection. Glowing with joy, I now had everything I needed for the display.

The Oxford University Museum of Natural History

The Corsi Collection

Natasha Gertler and Monica Price with the Corsi collection

Stone slabs of Sicilian jaspers from the Corsi collection, corresponding to those present in the Courtauld frame

Illuminating Objects: Observation, Connoisseurship and a bit of Detective Work

Illuminating Objects intern Natasha Gertler tells us about how her research is going. 

As previously touched upon in my last blog post (and frankly, contrary to my natural instinct to apply analysis to any given problem) identifying decorative stones, such as those in the Courtauld’s ornate frame, is actually more an art than a science.

Whereas geologists can use destructive techniques to analyse and accurately identify rocks and minerals from the field – smashing and slicing them to view under a microscope – this of course is not an option when considering valuable objects from a museum collection. Even most non-invasive analytical techniques are inappropriate as the majority of these aim to establish information about the chemical composition and arrangement of a sample but many materials, both natural and manmade, have essentially the same chemical make-up. For example, both quartz and glass are composed of silica (SiO₂) and so cannot be distinguished by such analysis.

Therefore, identifying decorative stones is normally achieved through a mixture of observation, connoisseurship and comparison to stones of known identity. Awareness of such stones, their appearance, uses and provenance, is hence essential for identification. However, this is rather a niche discipline as it lies somewhere between geology and art history but is never fully taught in either field, but instead gained through experience and exposure. There are only a handful of such experts in the UK.

Dr. Ruth Siddall, Senior Lecturer in Earth Sciences at UCL, along with her student, Nadine Gabriel, kindly came to the Courtauld to lay eyes on the frame and carry out a bit of detective work. Armed with a microscope and a wealth of decorative stone knowledge, Ruth corrected our prior suspicions of the inclusion of man-made imitations in the frame, reassuring us that all the segments of the frame were indeed rocks and minerals sourced from around the 17th century.

Ruth Siddall and Nadine Gabriel observing the frame

Microscopic camera taking images of the frame

Natasha Gertler and Nadine Gabriel looking at the microscopic images of the frame

Ruth’s certainty arose by comparing the stones in the frame to the extensive Corsi collection. Housed in the Oxford University Museum of Natural History, it is composed of 1000 polished stone slabs of uniform shape and size (145 x 73 x 40 mm). By referring to the online catalogue, she identified the presence of various Sicilian jaspers in the frame.

In particular, Ruth identified what we initially thought was an imitation of tiger’s eye to in fact be a distinct variety of Sicilian jasper characterised by its yellow and black banded appearance. Shown below are images of the Sicilian jaspers in the frame (left) alongside the corresponding samples from the Corsi collection (right).

Corsi 764 © Oxford University Museum of Natural History

Corsi 745 © Oxford University Museum of Natural History

Corsi 776 © Oxford University Museum of Natural History

Ruth Siddall using the Corsi collection online catalogue for comparisonWith such an excellent resource on our doorstep, naturally our next step on the quest for identity was to contact Monica Price, Head of Earth Collections at the Oxford University Museum of Natural History and author of The Corsi Collection website.

Read all about my collaboration with Monica Price and trip to the Oxford University Museum of Natural History in my next blog post.

P.s. As the major contributor of information to the London Pavement Geology website, Ruth also pointed out to us the decorative stones used just on the doorstep of the Courtauld. These are Grey Oland Limestone and Red Oland Limestone arranged in a checkered pattern. Admittedly, I have never noticed these details, so next time you come and visit us make sure to spot the ancient fossils under your feet!

Reading Inscriptions in the Collection

Our Reading Drawings Display, in the Gilbert and Ildiko Butler Drawings Gallery until 4 June, looks at a selection of works from The Courtauld Gallery’s collection which demonstrate the varying reasons both artists and collectors wrote on drawings. These range from straightforward signatures to lengthy captions, invented languages and marks of ownership. However, it’s not just this temporary display that features inscriptions revealing essential information about a work of art’s authorship, dating, subject matter, purpose and history. The Courtauld’s full collection has its own plethora of written word on a variety of materials, detailing an array of interesting snippets of information.

Monumental Inscriptions

Roman funerary altar (1st century AD)

Roman funerary altar (1st century AD)

The inscription here mentions the stone was made by Lucceia Hebene for her husband, Marcus Lucceius Optatus, and daughter, who died at five years and three months. What it does not tell us, but can be deduced from the name itself, is that Hebbene (or Hebene) was a freed slave, possibly a black freed slave. (There is an associated altar, dedicated to Lucceia Hebene herself, in a castle in Scotland.)

The art and craft of lettering

Inscription, 1918, Eric Gill (1882-1940)

This carved limestone inscription reads ‘OPTIMA ET PULCHERRIMA VITAE SVPELLEX AMICTIA’. This is adapted from Cicero’s De Amicitia and means ‘The best and most beautiful support of life is friendship’. Inscribed on the right side is the name of the sculptor and date of the work, ‘EGill 1918’.

Monograms and signatures

Portrait of Mette Gauguin, 1877, Paul Gauguin

The inscription on this bust is signed and carved below the collar: P. Gauguin. Only two marble sculptures by Gauguin are known, this portrait head of his Danish wife Mette and one of his son, Emile, carved in the same year. At the time the Gauguin family was living in an apartment in the Rue des Fourneaux, in Paris, which belonged to a sculptor named Bouillot. Considering Gauguin’s inexperience as a sculptor in marble, and the highly accomplished naturalism of this work, it seems likely that Bouillot assisted Gauguin in the carving, but to what extent is not known.

Virgin and Child, Circa 1365-70, Barnaba da Modena

This small work was made for private devotion. For this purpose, Christ’s scroll is inscribed with one of the beatitudes: ‘Blessed are the poor in spirit’. The text along the bottom, ‘Barnaba da Modena painted (this)’, is a rare early example of a painter’s signature. Born in Modena in central Italy, Barnaba spent most of his career in Genoa. The heavy shading of the Virgin’s face and the gold striations on her mantle are derived from Byzantine art. This slightly archaic style may account for Barnaba’s success in Genoa, where Byzantine painting had long been dominant.

Enamel plaque painted in grisaille with David and Goliath, probably French 19th Century in the style of the 16th century

This enamel plaque shows David and Goliath, with ‘P.R.’ on the bottom of the triumphal arch. Signed enamels with the monogram ‘P.R.’ usually means they were either made in the ‘workshop of Pierre Reymond’, or by Pierre Reymond himself. However, it is thought that this work is a highly skilled 19th century forgery done in the style of Pierre Reymond.

These are just a few examples of the types of inscriptions that can be found within The Courtauld Gallery’s collection, both online and in the Gallery itself. Next time you’re visiting us, why not take a closer look at the works and delve into the world of writing and markings on works of art, and for all art that is not currently on display, you can find out more on them on our Art and Architecture website.

Visit Reading Drawings, on display until 4 June 2017

The Courtauld Gallery Café

The Courtauld Gallery Café is an oasis of calm set within the elegant surroundings of Somerset House.The Café has indoor and outdoor seating and is the perfect spot to relax and unwind. The team of chefs ensure that delicious seasonal food is made on site all year round including freshly baked cakes, salads, soups and light meals. We spoke to Café Manager, Karolina Grazulyte about her role and whats it like work at The Courtauld Gallery.  

Tell us about your role at The Courtauld Gallery?

I work as a General Manager in both: The Gallery and Student cafés here in Courtauld.

What does your job involve on a daily basis?

I don’t think I ever have a ‘typical day’. In catering industry every day is different from another and brings new challenges! My main responsibility is to manage two Courtauld cafés sand provide catering and hospitality for various events. Enough to keep myself busy!

What’s your favourite thing about being working at The Courtauld Gallery?

I think it’s the fact that I have a privilege to work in a gallery with such a superb collection which includes world-class masterpieces.

 What is your work of art in The Courtauld collection?

It is really hard to choose just one; however, my favourite piece is Édouard Manet ‘A Bar at the Folies-Bergère’. Not only because of its popularity and the fact that it was Manet’s last major work, but I like the mystery which can be found looking in the mirror at the counter. I also admire it because every time I look at it I can discover a new details – like a pair of green feet in the upper left-hand corner!

Finally, what’s your favourite item on the Café menu?

My favourite dish is free range chicken salad with blood orange, chicory, mange tout and mint vinaigrette. It is very healthy, light and full of flavour!

Visit Karolina in The Courtauld Gallery Café Open daily 10.00 – 17.30

 

Illuminating Objects: More Than Meets The Eye

Our Illuminating Objects project for 2017 is now underway. In a series of blog posts postgraduate intern Natasha Gertler will share her discoveries as she chooses and researches the next Illuminating Object.

With an academic background in physics and an unwavering curiosity for crystals since, well, forever, it was only natural for me to choose the intricate frame bearing the double sided Aertsen painting for my ‘Illuminating Objects’ internship. Acquired by Count Seilern in 1969 from Alessandro Orso in Milan, the frame is beautifully inlaid in pietra dura with a multitude of semi-precious stones.

Or so we thought…

Upon initial inspection (which, by the way, was true love at first sight) and discussion with Sacha, Curator of Sculpture and Decorative Arts with whom I am working on this project, and Graeme, Chief Conservator, we had speculations of the material composition of the frame; that the central upper disc showing concentric red and white rings was pink agate, the two purple columns either side of the painting were amethyst and the several rich blue segments, lapis lazuli. But, as with most scientific investigations, things are not often as they seem and we needed to perform analytical experimentation to be sure.

In order to gain some insight into the constituent elements of the stones, we ventured down to the conservation laboratory of the Courtauld to use the X-ray Fluorescence (XRF) facilities, with the expert guidance of Professor Aviva Burnstock and Silvia Amato.

Having used spectroscopy many times in my undergraduate physics experiments (albeit on far less beautiful objects!) I felt quite at home and even a little nostalgic in the Courtauld’s lab. XRF works by shooting X-rays at a sample and then analysing the energies of the X-rays reflected back to the detector, which are characteristic to each individual element.

As expected, areas of red colour showed a dominance of iron (Fe) in their spectrum, and the dark blue areas exhibited the presence of Calcium (Ca) which is typical of lapis lazuli. However, many different stones as well as manmade materials also have several elements in common with each other. For example silicon (Si) is present in both agate and glass. Therefore, XRF cannot be used as a conclusive method of material identification, but rather as a further analytical tool.

Red, round element in the central upper area. Presence of silicon and iron.

Central blue segment below the painting. Presence of calcium.

Purple element, middle horizontal element below columns. Presence of silicon.

For that reason, we turned to visual analysis instead. Dr. Emma Passmore, a senior teaching fellow in Earth Sciences at Imperial College London with experience in object analysis for the British Museum, kindly came to the Courtauld’s depot to help us identify these mystery materials. She agreed with our initial theories and added that the mirroring light blue elements on the lower panel were also agate.

However, she also suggested that some of the segments might not be semi-precious stones at all, but rather synthetic imitations. These included for example the panels that look like tigers eye and the red ovals at the very bottom, as well the orange and purple coloured banners across of the top and bottom of the painting, respectively.

Professional geologists identify stones by smashing and slicing them to make slides which they can then analyse under a microscope to a very high degree of accuracy. However, in the case of historically important and valuable objects such as this unique frame, this of course is not an option and alternative, non-intrusive methods must be used instead.

Will we ever be able to know the materials present in the frame with absolute certainty? Perhaps. And so the quest for identity continues…

 

Illuminating Objects is a series of displays that shines a light on unexpected objects from The Courtauld’s decorative arts and sculpture collection.