Lava medallions and coins in lava from Mount Vesuvius, Italy

The National Museum Wales Petrology (Rock) collection comprises 35,000 specimens, with many interesting rock samples from across Wales and the wider World. In the drawers of the Italian collection, alongside the pumice, volcanic ash and obsidian are these curious rocks.

What are lava medallions?

They are called lava medallions, medals or tablets, and along with coins embedded in lava they were probably first produced in the mid-18^th Century when the ‘Grand Tour’ become fasionable among the wealthy elite of Europe.  Taking in European cities like Paris, Rome, Venice, Florence and Naples, the ‘students’ would travel with a tutor on a Grand Tour to learn about languages, geography, culture, art and architecture. When passing through Naples, the volcano of Mount Vesuvius (Vesuvio) became a must see stop on the tour. Forget postcards, fridge magnets and selfies, the take home souvenir of the day was the lava medallion!

People have long been fascinated by destructive power of Mount Vesuvius, the volcano had lain dormant for centuries before the famous eruption in 79 A.D. when the Roman cities of Pompeii and Herculaneum were destroyed. Over the last two thousand years, the volcano has erupted many times. Between eruptions, Vesuvius can lie almost dormant for long periods of time before erupting violently once again. Volcanoes the world over that erupt in this explosive style after long periods of dormancy are known as Vesuvian eruption volcanoes.

How were lava medallions made?

To make a lava medallion, molten lava would have been retrieved (by some very brave individual with a long stick!) from a recent lava flow or lava close enough to the surface that was accessible and still hot enough to be malleable. It was then moulded, pressed with a stamp, or embedded with a coin, cooled in a bucket of water and sold to a passing grand tourist.

The French Revolution in 1789 marked then end of Grand Tours as they were known, but with the advent of the railways in the early 19^th Century and the beginnings of mass tourism, these distinct souvenirs once again became popular take-home keepsakes, and they were produced in their thousands.

Over the years many of these medallions and lava coins have found their way into museum collections across the world. They often depict kings, Roman Emperors, famous scientists or events. All of the medallions and coins in the AC NMW collection date from the 19^th Century, and originate from Mount Vesuvius, but examples in other collections have originated from Mount Etna, Sicily.

If you would like to know more about lava medallions, please contact Andrew Haycock via:

https://museum.wales/staff/665/Andrew-Haycock/

Helo Cyfeillion y Gwanwyn,

Mae'n bron diwrnod plannu ar gyfer ysgolion yn Gymru, Lloegr a Gogledd Iwerddon! Bydd ysgolion yn Yr Alban yn plannu wythnos nesa.

Cliciwch yma ar gyfer adnoddau i'ch paratoi ar gyfer heddiw ac am ofalu amdan eich bylbiau dros y misoedd nesaf!

Dylech ddarllen y dogfennau hyn:

• Mabwysiadu eich Bwlb (trosolwg o’r gofal fydd angen ar eich Bylbiau)

• Plannu eich bylbiau (canllawiau ar gyfer sicrhau arbrawf teg)

A chwblhewch y gweithgareddau hyn:

• Tystysgrif Mabwysiadu Bylbiau

• Creu Labelai Bylbiau

Mae'n bwysig eich bod yn darllen y rhain oherwydd maent yn cynnwys gwybodaeth bwysig! Er enghraifft, ydych chi'n gwybod i labelu eich potiau fel mae’n glir lle mae'r Cennin Pedr a Chrocws wedi eu plannu?

Cofiwch dynnu lluniau o'ch diwrnod plannu i gystadlu yn y Gystadleuaeth Ffotograffydd Diwrnod Plannu!

Cadwch lygad ar dudalen Twitter Athro'r Ardd i weld lluniau o ysgolion eraill.

Pob lwc! Gadewch i ni wybod sut mae'n mynd!

Athro'r Ardd a Bwlb Bychan

The medieval court, Llys Llywelyn, has finally opened its doors. The hall transports us back to a day in the 13th century when Llywelyn ap Iorwerth, Prince of Gwynedd is in residence and about to hold court. The recreated sumptuous decoration, furnishing and ornament reflects both his wealth and status, most of the portable items travelled with him as he progressed around his kingdom so were only present when the prince was in residence.

One way to reflect your wealth and status in the medieval period was through the use of colour. There were a wide range of artist's pigments available from which paint could be make, some were natural minerals like the bright red vermilion and others where man-made such as Verdigris, a green-blue colour created by suspending copper plates over vinegar or the waste from the wine making process.

Our mission, along with the painters from the Historic Buildings Unit and volunteers from our Preventive Conservation Group, was to recreate the painted interior of the 13^th century court. All was to be authentic including the pigments and paint medium we used. The wooden columns and arches were still drying out so whatever we applied had to be breathable, but also robust enough to cope with the thousands of visitors we welcome each year.

Paint is made up of two elements, a coloured pigment and a glue referred to as the paint medium. There were a variety of traditional mediums we could use such as gelatin, extracted by boiling up scraps of parchment made from the skin of sheep, calves or goat. Other options included egg and also casein derived from milk.

As you can see the options available were very 'organic' and certainly not familiar. Our only guides were the few remaining texts on the subject and analytical evidence from surviving paintwork.

Which paint mediums did we choose in the end?

Egg was an option, but it would have taken an awfully large number of eggs and been a bit smelly while the egg off-gassed sulphur during the paint setting process!  We therefore started to trial gelatin in combination with the white pigment calcium carbonate for the background and red ochre pigment for the chevrons. This proved very successful for the white background but less so for the red chevrons. The next option was casein, this produced a much more robust finish and therefore was chosen in combination with the red ochre pigment for the chevrons.

One thing we learnt during this process was that our work had to be slow and methodical, traditional materials can't be rushed. We developed a huge respect for the medieval painter and the skill required when using these tricky materials to create decoration or works of art.

Finally I wish to thank all our volunteers for their help to deliver this project. We could not have done it without them and yes we spent a lot of time watching paint dry, praying it wouldn't flake off!

"If you asked me what a magelonid was 18 months ago, I would have looked at you with a somewhat muddled expression. Let me tell you, a lot has changed since then. Roll onto the present day, after a year at Amgueddfa Cymru – National Museum Wales for my Professional Training Year (as part of my Zoology degree at Cardiff University), I could talk for as long as you are willing to listen about this fascinating family of marine bristle worms, commonly known as the shovel-head worms (Annelida: Magelonidae)."

            When my application was first approved from the Natural Sciences Department at the museum, I didn’t know what to expect. I had always loved anything marine and knew from the start this is the area I wanted to build a career around. This was a very broad declaration and beyond this, I was rather diffident in what I wanted to pursue. Therefore, my number one priority was to keep an open mind and make the most of everything the experience would offer. This view shaped a year filled with opportunities, that has not only been indispensable in developing my scientific skills in both hands on research and writing, but also in giving me a direction I am interested in for the future. 

            The majority of the placement involved both behavioural and taxonomic studies on European magelonid species, through the practicing of methods such as time-lapse photography, live observation, scanning electron microscopy, high definition photography using a macroscope, and taxonomic drawings using a camera lucida attached to a microscope. As a result of this work, some very interesting findings were highlighted for the Magelonidae, with important implications for furthering our understanding of these enigmatic animals. Perhaps the most fascinating arose through extensive time-lapse photography and observing animals in aquaria within the marine laboratory, in which an un-described behaviour emerged in the tube dwelling species Magelona alleni. Later termed as ‘sand expulsion’, this behaviour was a highly conspicuous method of defecation where M. alleni would turn around in a burrow network, raise its posterior region into the water column and excrete sand around the tank. Just knowing I was most likely the first person to ever witness this was a very rewarding experience in itself! To understand why this novel behaviour was exhibited, the posterior morphology of M. alleni was compared to additional European species. These findings have led onto my first publication in a peer-reviewed journal, of which two more papers and an article are due to follow as a result of working closely with my supervisor throughout the year.

I also got the opportunity to participate in tasks that are essential to the upkeep of the museum, such as curation, specimen fixation and preservation, along with invertebrate tank maintenance. Additionally, I participated in sampling trips, including a visit to Berwick-upon-Tweed and outreach events, such as ‘After Dark at the Museum’, which saw over 2,000 visitors, and the RHS show Cardiff.   

            Overall, the museum is a very friendly, intellectual and dynamic environment that has more to offer than perhaps meets the eye. This is why anyone who wants to study the small, whacky and wonderful world of marine invertebrates should not pass up an opportunity to undertake a placement here. Spend any prolonged amount of time amongst the hundreds of thousands of specimens kept in the fluid store, and I guarantee you will not be able to escape a visceral appreciation of the natural history of our world. With this comes a feeling of preservation for all we have and a reinforcement of why museums are such a crucial component of our society today, something that is too easily forgotten. 

Read more about Kim's journey through her PTY Placement at National Museum Cardiff:

https://museum.wales/blog/2017-08-04/A-new-world-of-worms---beginning-a-Professional-Training-Year-at-the-museum/

https://museum.wales/blog/2017-11-15/A-tail-of-a-PTY-student/

https://museum.wales/blog/2018-02-07/The-early-bird-catches-the-worm/

Over the past few months the museum has been working closely with colleagues at the beautiful Oriel y Parc gallery in St Davids to bring together an exhibition celebrating Wales ‘Year of the Sea’ called ‘Coast’.

The exhibition fuses artworks and natural science specimens specially selected by the Oriel y Parc team from Amgueddfa Cymru’s collections, and displays these alongside some of the recent museum activisim work of Amgueddfa Cymru’s 'Youth Forum Group' highlighting the issues of plastic pollution.

The multidisciplinary nature of the display explores how the sea has inspired artists for centuries, highlights the biodiversity of the Pembrokeshire coast, and how plastic now impacts on the environment and our everyday life.

Centre piece to the art works is Jan van de Cappelle’s masterpiece ‘A Calm’, surrounded by sea and coast inspired paintings from a selection of other artists including Cedric Morris and John Kyffin Williams. Amongst these works are specimens from the natural science collections capturing the richness of Pembrokeshire's wildlife, including the skeleton of a leatherback turtle found dead on Skomer Island in 1988.

The turtle had in the past been on display at the visitor centre on Skomer, but was removed a number of years back when the buildings on the Island underwent redevelopment. In need of some repairs and cleaning, the specimen became an excellent project for one of our conservation student placements at the museum, Owen Lazzari. The end result has enabled us to bring the specimen back to Pembrokeshire to form one of the centrepieces of the exhibition.

Other highlights from the natural science collections include one of our historic Blaschka glass models dating from the late 1800s, and a Goose barnacle covered builder's helmet found off the Welsh Coast.

Further information can be found on Oriel y Parc's website: https://www.pembrokeshirecoast.wales