: Hanes Naturiol

Written by Caitlin Jenkins, MSc Conservation Practice student, Cardiff University

I’m Caitlin, an MSc Conservation Practice student from Cardiff University and I have just finished my summer placement at National Museum Cardiff. I’ve been working with conservator Julian Carter on the natural history collections, with the last five weeks focused on preparations for the museum’s summer exhibition, Snakes!

The first week saw me elbow deep in jars full of snakes, as we worked our way through getting 32 fluid preserved specimens ready for display. Although the snakes had already undergone previous treatment, many were very old and in need of attention. After checking the jars’ condition, we added or replaced conservation fluid as required.

Many snakes needed to be rehomed in new jars. Some preservationists use wires or mountings, but we chose to follow the natural shape of the snake and its flexibility to guide its positioning within the jar. My favourite of the specimens was a grass snake that had been preserved in the act of eating a toad (with one leg dangling from its mouth...poor toad!)

I was also able to assist with preserving a new addition to this collection – a boa constrictor named Aeron. After formaldehyde injections and several fluid changes, we needed to find an extra-large shiny new jar, because he was over a metre long. Aeron has now bagged a starring role as the centrepiece of his display case. I really enjoyed this experience, and it has given me a fantastic insight into the complexities and potential of fluid preservation.

My other major project was the treatment of three snake models destined to be part of a large interactive exhibit within Snakes! Two were painted plaster models of a rattle snake and a king cobra. These incredibly detailed antiques were perhaps cast from real specimens. The third was a moulded rubber and polystyrene grass snake model from the 1960s. The models had survived in remarkably good condition given their age, they just needed a little ‘zhoosh’ to make them display-ready. Light brushing and swabbing with water and mild detergent was all that was needed to remove ingrained dust. Any loose or flaking areas were consolidated to ensure that they didn’t become further detached from the model.

Nevertheless, small elements were missing from each model. The grass snake model posed a specific conservation risk, as rubber and plastics can become unstable over time. Its tongue became fragmented during cleaning and unfortunately proved too badly degraded to reattach. Using photographs of the real-life snake species as a guide, I fashioned replacement tongues for this and the king cobra model from a strong plant-based fibre known as Japanese tissue. They were secured in place and painted to blend them into the jaw area. Being able to see the immediate improvement after each snake ‘facelift’ was very satisfying - this took cosmetic surgery to a whole new level!

Finally, the finished models were settled into their new home for the summer – a large interactive exhibit affectionately dubbed ‘the snake pit’. I’d become so immersed in their treatment over the last five weeks that I was kind of sad to see them go – but it was satisfying to see them looking their best and used in the spirit for which they were originally created.

I’ve really enjoyed working on Snakes! from preparation to completed display – it’s been a fantastic experience. If you are in the vicinity of the museum, pleasssse pay them a visit.

The exhibition runs till 15th September 2019, entry charges do apply, and all your contributions go towards bringing you even bigger and better exhibitions in the future. Please note that there is no live handling of the snakes within the exhibition, there will be a series of bookable handling sessions throughout the summer as well as a Venom themed Open Day in August. To find out more about all of this, go to our What's On page.

On the 22nd June our new summer exhibition opened. This family friendly exhibition runs until September and delves into the captivating life of snakes, helping you to find out more about these extraordinary and misunderstood creatures. We are hoping to feature more detailed stories about all of the things mentioned below in a series of blogs running through July and August so keep tuning in to find out more.

Snakes is a touring exhibition created by a company called Blue Tokay with added bonus content generated by our team. Work began on bringing together all of this way back in September 2018 and since then we have been busy researching, writing text and preparing some great specimens for you all to enjoy.

The main exhibition covers all aspects of the lives of snakes, so we focused our efforts on highlighting our collections at the museum. We hold over 3.5 million natural history specimens here, and as you can imagine, not everything is on display. We hold a small collection of 500 reptiles from all over the world. These are mostly preserved in alcohol and stored in jars, but we also have skeletons, skins and eggs. We chose 32 of our best snakes to go out on display. Each of these were carefully rehoused and conserved as many of the specimens were old and in need of work.

But it’s not just snakes in jars. We have also displayed some fantastic casts of 49 million years old fossil snakes, and 3D printed the vertebra of Titanoboa, the largest snake that ever lived.

One of my favourite features of the exhibit are our objects dealing with snake folklore and mythology, featuring a 13^th century manuscript showing how snakes were used in medicinal remedies. Also some fantastic ‘snakestones’, actually fossil ammonites with snake heads carved on to the top.

You may also recognise the statue of Perseus that has long been displayed in our main hall. Perseus is enjoying his new surroundings, with Medusa’s snake ridden head looking positively sinister with the new lighting.

The exhibition features six live snakes and as I’m sure you can imagine, bringing live animals into a museum requires a LOT of preparation. We have done a great deal of work to ensure that their time with us is spent in 5 star accommodation. Their ‘vivaria’ are purpose built to ensure our snakes are well cared for, including warm and cool spots, as well as a water feature for a bathe. We have a fantastic (and very brave) set of staff who are volunteering their time to looking after them including changing water bowls, and clearing up their poo! Dr Rhys Jones (Cardiff University) has been fantastic with helping throughout this whole process, including coming in every week to feed them. The snakes are all provided by a company called Bugs n Stuff, you can see a video of them installing the live snakes here.

Finally, our fantastic learning department, design team and technicians have worked hard to add some fun activities for all to enjoy. Our Spot the Snake pit features, amongst other things, two beautifully conserved models of a cobra and a rattlesnake that date back to 1903, and a real freeze-dried adder! We also have a snake expert quiz, a world map of snakes, and drawing and colouring stations. Volunteers will be in the gallery periodically across the summer with snake handling specimens including a real full length skin of an African Rock Python.

The exhibition runs till 15th September 2019, entry charges do apply, and all your contributions go towards bringing you even bigger and better exhibitions in the future. Please note that there is no live handling of the snakes within the exhibition, there will be a series of bookable handling sessions throughout the summer as well as a Venom themed Open Day in August. To find out more about all of this, go to our What's On page.

Mae’n fis Mehefin ac rydym wedi dewis silicon i fod yn elfen y mis. Efallai na fyddai rhywun yn meddwl yn syth bod i silicon arwyddocâd arbennig i Gymru, ond mae iddo hanes diddorol.

Mae silicon (symbol cemegol – Si, rhif atomig – 14) yn solid crisialog caled ond brau, sydd â sglein metalig llwydlas. Silicon yw’r elfen fwyaf cyffredin ond un (tua 28% o ran màs) yng nghramen y Ddaear. Ocsigen yw’r elfen fwyaf cyffredin ac mae i’r ddwy elfen affinedd cryf. O ganlyniad i hynny, cymerodd tan 1823 i wyddonydd – Jöns Jakob Berzelius – baratoi silicon yn ei ffurf bur.

Yng Nghymru, mae silicon i’w gael ym mhobman bron ar ryw ffurf neu’i gilydd: o gwarts (silicon deuocsid, SiO₂) mewn tywodfeini, amryfeini a cherrig silt gwaddodol; i silicadau cymhlyg mewn creigiau igneaidd a metamorffig; a gwaddodion mewn priddoedd.

Bu silica (silicon deuocsid, neu gwarts) yn cael ei gloddio’n helaeth yn ardal Pontneddfechan, de Powys, o ddiwdd y 18^fed ganrif tan 1964 a’i ddefnyddio i wneud brics tân ar gyfer odynau a ffwrneisi. Mae’n digwydd ar ffurf deunydd pur iawn o ddwysedd uchel mewn cwartsit mewn uned ddaearegol o’r enw Grutfaen Gwaelodol neu Dywodfaen Twrch. Wrth i’r cwartsid gael ei hindreulio a’i erydu, gadawyd dyddodion o dywod silica a gafodd ei gloddio'n helaeth i wneud brics tân gwrthsafol ar gyfer y diwydiannau mwyndoddi.

Yn y gogledd, bu masnach weddol ddi-nod mewn creigrisial – math di-liw, tryloyw o grisial cwarts – yn Eryri yn ystod y 18^fed ganrif a’r 19^eg ganrif wedi’i chanoli o gwmpas pentref Beddgelert. Mae T. H. Parry-Williams yn cyfeirio at hyn yn un o’i Ysgrifau.  Roedd mwynwyr a thywyswyr mynydd yn chwilota am wythiennau cwarts yn y mynyddoedd ac yn casglu crisialau i’w gwerthu i dwristiaid. Mae’n bosib bod rhai wedi'u defnyddio i wneud canwyllyrau crisial. Yn ddiweddarach, câi crisialau eu canfod yn achlysurol yn y chwareli llechi enfawr neu wrth fynd ati ar raddfa fawr i greu lonydd ar dir fforestri yn yr 1960au.

Mae silicon, ar ffurf silica (enw arall am silicon deuocsid) yn bwysig i rai organebau hefyd, yn enwedig ddiatomau a sbyngau.

Algâu microscopig ungellog sydd â chellfur cymhlyg wedi'i wneud o silica yw diatomau. Maent i’w cael yn helaeth ym mhob math o ddŵr, maent yn cynhyrchu ocsigen a chânt eu bwyta gan organebau eraill yn y dŵr. Yn aml, defnyddir diatomau i fonitro ansawdd dŵr.

Mae sbyngau’n adeiladu eu sgerbydau o fframwaith o elfennau bychan, bach o’r enw sbigylau. Yn y rhan fwyaf o grwpiau o sbyngau, gwneir y rhain o silica.  Ymhlith yr enghreifftiau harddaf mae sbwng gwydraidd Cawell Gwener, sy’n byw wedi’i angori wrth wely’r dyfnfor ger y Philipinau.  Mae pâr o berdys yn byw y tu mewn i’r sbwng, gan baru y tu mewn a threulio’u holl fywyd wedi’u gwarchod oddi mewn i’r waliau gwydraidd cain.  Diolch i’r berthynas symbiotig anghyffredin hon, mae sgerbydau marw Cewyll Gwener yn anrheg briodas boblogaidd yn Japan.

Sbyngau yw’r math mwyaf cyntefig o anifail ar y Ddaear, ac mae eu sbigylau gwydn yn ymddangos fel ffosilau yn dyddio o hyd at 580 miliwn o flynyddoedd yn ôl. Yn ogystal, mae silica’n chwarae rhan bwysig yn gwarchod mathau eraill o ffosilau.  Pan gleddir anifeiliaid neu blanhigion marw, gall silica o ddŵr daear lenwi’r mandyllau a mannau gweigion eraill mewn pren, esgyrn neu gregyn, a/neu gall gymryd lle’r deunyddiau gwreiddiol wrth iddynt bydru neu hydoddi.   Mae hyn yn digwydd amlaf mewn ardaloedd lle mae llawer o silica yn y dŵr daear, oherwydd gweithgaredd folcanig neu am fod creigiau ac ynddynt lawer o silica wedi erydu.   Mae’r olion organig yn ganolbwynt ar gyfer ffurfio deunyddiau silica, ac yn aml mae’r graig sydd o gwmpas y ffosilau wedi’i gwneud o fwynau gwahanol.  Er enghraifft, wrth i gregyn a wnaed yn wreiddiol o galsiwm carbonad hydoddi, gall silica gymryd lle’r calsiwm carbonad, a chânt eu ffosileiddio mewn calchfaen (calsiwm carbonad).  Mae’n hawdd tynnu’r ffosilau trwy roi’r graig mewn asid a disgwyl iddi hydoddi, gan adael y ffosilau a siliceiddiwyd ar ôl.  Yng nghasgliadau ffosilau’r Amgueddfa, ceir llawer o gregyn wedi’u siliceiddio – braciopodau, amonitau, bryosoaid a chreaduriaid morol eraill.

Un o’r mathau mwyaf trawiadol o ffosil a siliceiddiwyd yw ‘pren petraidd’.  Daeth silica i gymryd lle celloedd gwreiddiol y pren wrth iddo bydru ac i lenwi unrhyw fylchau, gan ei ‘droi’n garreg’ yn llythrennol.  Mewn rhai mannau, yn cynnwys Patagonia a'r Unol Daleithiau, gwelir bonion coed cyfan lle disodlwyd y pren gan silica yn yr hyn a elwir yn ‘fforestydd petraidd’.  Ceir planhigion eraill, fel conau, wedi’u ffosileiddio fel hyn hefyd.

Craig a wneir o grisialau bach iawn o silica yw cornfaen neu siert.  Ffurfiwyd llawer o ddyddodion cornfaen mawr ar waelod cefnforoedd hynafol o ‘forlaid silicaidd’, a wnaed o sgerbydau miliynau o organebau bach iawn yn cynnwys diatomau a rheiddiolion (plancton ungellog).  Gall cnepynnau cornfaen ffurfio oddi mewn i greigiau eraill hefyd trwy brosesau cemegol.   

Gelwir cornfaen sydd mewn sialc yn fflint, a bu’n ddeunydd pwysig iawn ar gyfer gwneud tŵls yn y cyfnod Cynhanesyddol. Gwneir y tŵls trwy naddu’r fflint, hynny yw trwy daro ymyl y fflint sydd wedi’i baratoi, neu lwyfan taro, â charreg galetach er mwyn rhyddhau darnau o’r enw naddion neu lafnau.  Yna, gellir addasu’r naddion neu’r llafnau hyn ac, yn wir, y craidd y cânt eu taro ohono a’u gwneud yn dŵls cywrain. Ymhlith y rhai mwyaf cywrain mae pennau saethau main, yn cynnwys y rhain o fedd o’r Oes Efydd yn Breach Farm, Bro Morgannwg. Gan amlaf, fflint oedd y dewis cyntaf ar gyfer gwneud offer torri miniog am fod ei raen mor fân a’i fod yn hollti’n gregynnaidd ac yn lân i roi ymyl dorri finiog iawn. Yn wir, i’r fath raddau nes bod straeon am lawfeddygon y llygad yn defnyddio llafn fflint newydd ei dorri i drin llygaid cleifion weithiau!

Gan fod graen mân iawn i gornfaen a’i fod yn galed iawn, gall ddal ffosilau o bethau bach iawn o gyfnod pell iawn yn ôl yn hanes ein planed.  Credir mai mewn cornfeini y ceir y ffosilau hynaf ar y Ddaear, ac maent yn cynnwys olion posibl bacteria dros 3 biliwn o flynyddoedd oed.  Mae ffosilau iau, o Gornfaen Rhynie o ogledd yr Alban, yn rhoi cipolwg i ni ar un o’r cymunedau cynharaf ar dir, 400 miliwn o flynyddoedd yn ôl.  Cadwyd manylion cywrain planhigion ac anifeiliaid syml, yn cynnwys creaduriaid cyntefig tebyg i gorynnod, a sgorpionau, diolch i ddŵr llawn silica o ffynhonnau folcanig poeth.

Math hydradol o silica yw opal, sy’n golygu ei fod yn cynnwys rhwng 3 a 21% o ddŵr.  Yn wahanol i silica arferol, nid oes iddo ffurf crisialog penodol, ond mae rhai o’i ffurfiau’n diffreithio goleuni, gan greu effaith symudliw hardd mewn nifer o wahanol liwiau.  Am y rheswm hwn, mae opal wedi’i werthfawrogi ers canrifoedd fel gem ar gyfer gwneud tlysau crog, modrwyau a mathau eraill o emwaith.  O Awstralia y daw llawer o opal y byd, ac fe geir yno ffosilau prin ac ysblennydd wedi’u hopaleiddio hefyd.  Daeth opal i gymryd lle cregyn infertebratau fel belemnitau (creaduriaid cynhanesyddol tebyg i fôr-lewys [squid]), a hyd yn oed esgyrn deinosoriaid, gan greu sbesimenau lliwgar iawn mewn byd lle mai llwyd neu frown yw ffosilau gan amlaf.

Within Amgueddfa Cymru’s botany collections are books of dried plant specimens created by scientists and enthusiasts. Each specimen has been carefully dried and pressed, before being added to the books, sometimes with handwritten or printed notes alongside. The books are of enormous importance both in terms of modern scientific research into climate change and biodiversity, and as a way to see first hand the history of botanical exploration.

You can now look through a catalogue of the 36 books that contain non-flowering plants, fungi, lichens and seaweeds. You can read about a few of the stories surrounding these books below. For more detailed information about each book, please visit the website.

These books show the changes in how we collect, classify and name plants over two centuries from 1800 to present day. An old volume which probably dates from the 19^th century entitled “New Zealand Mosses”, contains more than just mosses. Lichens, algae and even some pressed hydrozoans (tiny marine animals) have been included by the unknown collector who chose to group these superficially similar ‘moss-like’ specimens together. This donation entered the Museum’s collections after its Royal Charter was received and before work had begun on the present Cathays Park building.

While the earliest currently known non-flowering plant specimen in the Museum is a moss collected in 1794 from Gwynedd, the earliest specimen book dates from 1803. This book is Lewis Weston Dillwyn’s personal collection of seaweed and freshwater algae collected between 1803 and 1809. Dillwyn’s specimen book was donated to the Museum in 1938 by the National Library of Wales, and has great importance both scientifically and historically.

Lewis Weston was part of the influential Dillwyn family, and his son John Dillwyn Llewelyn became an early pioneer photographer. He was interested in the natural history that he saw in south Wales where he lived. This is reflected in his scientific research as well as in the pottery designs created while he was owner of Cambrian Pottery. Dillwyn described new species of algae and his specimen book contains type specimens (irreplaceable specimens used in the original description of a species). The book is a personal record of his scientific life, recording places he visited and scientists who sent him specimens. He became a Fellow of the Royal Society in 1804 and later had a plant genus named after him in recognition of his work.

Many of the botanical specimen books in National Museum Cardiff have a fascinating history. Two contain mosses collected by Thomas Drummond on the Second Overland Arctic expedition between 1825 and 1827 to British North America (now Canada). Delving further into the book’s background reveals that the Captain, Sir John Franklin, sent Drummond to the Rocky Mountains with one Native American hunter. After the hunter left him on his own, he survived a severe winter, being mauled by a bear, and starvation. He still managed to collect, preserve and study many new plants of the North American continent. This work was published by Sir W.J. Hooker, who later became the director of the Royal Botanic Gardens, Kew.

The more recent books are systematically collected specimens known as ‘exsiccatae’. These are sets of duplicate specimens distributed by scientists to other museums. They help to spread the risk of losing a particularly important set of specimens, and to allow scientists around the world to study them. Lists of their contents are usually published in a journal or online. Much of the Berlin Herbarium and the botanical specimens within it was destroyed in World War 2, however many duplicate specimens from this collection survive in other herbaria around the world. From around the 1900s, exsiccatae changed from being bound books to being loose specimens. This meant museums receiving them could incorporate them into their collections alongside other closely related specimens for easier access and comparison.

Rydym yn parhau i nodi blwyddyn ryngwladol tabl cyfnodol yr elfennau cemegol ac, ar gyfer mis Ebrill, rydym wedi dewis calsiwm. Mae’r rhan fwyaf o bobl yn gwybod am galsiwm fel yr elfen sylfaenol er mwyn ffurfio esgyrn neu mewn calchfaen ond mae iddo lu o ddibenion eraill ac mae i'w gael ar wely'r môr ac mewn bywyd morol ddoe a heddiw.

Elfen fetelig o liw golau yw calsiwm (Ca) ac 20 yw ei rhif atomig. Mae’n hanfodol ar gyfer bywyd heddiw ac mae’n aml yn chwarae rhan bwysig yn cynnal planhigion ac anifeiliaid. Dim ond pedair elfen arall sy'n fwy cyffredin na chalsiwm yng nghramen y ddaear ac mae’n rhan o lawer o greigiau a mwynau fel calchfaen, aragonit, gypswm, dolomit, marmor a sialc.

Aragonit a calsit yw’r ddwy ffurf grisialog fwyaf cyffredin ar galsiwm carbonad ac fe gyfrannodd y ddwy at ffurfio’r ddwy filiwn o gregyn yn ein casgliad o folysgiaid. Craidd y casgliad hwn yw casgliad Melvill-Tomlin a gyfrannwyd i’r amgueddfa yn y 1950au. Dyma gasgliad rhyngwladol sy’n cynnwys llawer o sbesimenau prin, prydferth sy’n bwysig o safbwynt gwyddonol ac a ddefnyddir gan wyddonwyr o bedwar ban byd ar gyfer eu hymchwil. Caiff perlau, sydd hefyd wedi’u gwneud o aragonit a calsit, eu cynhyrchu gan gregyn deufalf fel wystrys, cregyn gleision dŵr croyw a hyd yn oed gregyn bylchog mawr. Ym myd natur, caiff perlau eu ffurfio wrth i’r molysgiaid ymateb i barasit ymwthiol neu ronyn o raean. Mae’r fantell o gwmpas corff meddal yr anifail yn gollwng calsiwm carbonad a conchiolin sy’n amgylchynu’r peth estron ac yn dynwared ei siâp ac felly nid yw pob un yn hollol grwn. Yn y diwydiant perlau, caiff pelenni bach iawn o gragen eu 'plannu’ yn yr wystrysen neu’r gragen las er mwyn sicrhau bod y berl a ffurfir yn hollol grwn.

Cyrff meddal sydd gan folysgiaid ac maent yn creu cregyn i fod yn darianau amddiffynnol iddynt. Mae hyn yn wir am anifeiliaid di-asgwrn-cefn eraill hefyd, yn enwedig yn y môr. Mae riffiau cwrel a thiwbiau rhai mwydod gwrychog (Serpulidae, Spirorbinae) yn dibynnu ar natur atgyfnerthol calsiwm carbonad i gynnal a gwarchod eu cyrff meddal. Mae gan gramenogion fel crancod a chimychiaid sgerbwd allanol caled sy’n cael ei atgyfnerthu â chalsiwm carbonad a chalsiwm ffosffad. O gastrolithau y daw’r calsiwm y mae ar gimychiaid, cimychiaid coch, cimychiaid afon a rhai crancod tir ei angen ar ôl bwrw’u cragen. (Weithiau, gelwir gastrolithau’n gerrig stumog neu'n llygaid crancod). Maent i’w cael ar y naill ochr a’r llall i’r stumog ac maent yn darparu calsiwm ar gyfer rhannau hanfodol o’r cwtigl fel darnau’r geg a’r coesau. Yng nghasgliad yr Amgueddfa, mae bron 750,000 o anifeiliad morol di-asgwrn-cefn, yn cynnwys cramenogion, cwrelau a mwydod gwrychog.

O fwynau calsiwm y gwnaed llawer o’r 700,000 o ffosilau sydd yng nghasgliadau’r Amgueddfa hefyd. Defnyddir dau brif fath o galsiwm carbonad i wneud cregyn a sgerbydau allanol anifeiliaid di-asgwrn-cefn, ac maent yn fwy tebygol o gael eu hanfarwoli fel ffosilau os defnyddir un ohonynt yn hytrach na’r llall. Mae aragonit, sydd yng nghregyn molysgiaid fel amonitau, gastropodau a chregyn deuglawr, yn ansefydlog ac nid yw’n para am filiynau o flynyddoedd gan amlaf. Wrth ffosileiddio, mae cregyn aragonit naill ai’n ymdoddi’n llwyr, neu mae’r aragonit yn ailgrisialu i ffurfio calsit. Defnyddiwyd calsit i wneud cregyn a sgerbydau grwpiau o gwrelau sydd wedi peidio â bod erbyn hyn, braciopodau cymalog, bryosoaid, ecinodermiaid a’r rhan fwyaf o drilobitau. Mae’n llawer mwy sefydlog nag aragonit ac felly mae darnau caled gwreiddiol o’r creaduriaid yn ymddangos fel ffosilau, filiynau o flynyddoedd ar ôl iddynt suddo i wely’r môr. Yn aml, gwelir grisialau mawr o galsit yn llenwi mannau gwag mewn ffosilau, fel y siambrau y tu mewn i gregyn amonitau. Mae fertebratau’n defnyddio mwyn calsiwm gwahanol i wneud esgyrn a dannedd: apatit (calsiwm ffosffad), a all bara am filiynau o flynyddoedd i wneud ffosilau eiconig fel sgerbydau deinosoriaid ac ysgithrau mamothiaid.

Yng nghasgliadau’r Amgueddfa o greigiau, mae llawer o galchfeini, creigiau a ffurfiwyd ar waelod y môr amser maith yn ôl o ddarnau o gregyn a deunydd arall sy’n cynnwys llawer o galsiwm carbonad. Ers miloedd o flynyddoedd, bu pobl yn defnyddio calchfeini i adeiladu: cerrig cerfiedig yn nhemlau eiconig y Groegiaid a’r Rhufeiniaid; darnau mâl i fod yn falast o dan reilffyrdd a ffyrdd; neu wedi’u llosgi i greu calch i wneud sment. Defnyddiwyd calchfaen enwog o Dorset o’r enw Carreg Portland i adeiladu Amgueddfa Genedlaethol Caerdydd ac adeiladau eiconig eraill yng Nghanolfan Ddinesig Caerdydd. Ar lawr yr Amgueddfa gwelir teils marmor, sef calchfaen a drawsnewidiwyd o dan wres a gwasgedd mawr. Bu cerflunwyr yn hoff iawn o farmor ers dyddiau’r hen Roegiaid a’r Rhufeiniaid. Yng nghasgliadau celf yr Amgueddfa gwelir gweithiau marmor gan Auguste Rodin, John Gibson, Syr Francis Chantrey, Syr William Goscombe John a llawer o rai eraill. Yn ogystal, mae yno enghreifftiau pwysig o waith gan gerflunwyr o’r ugeinfed ganrif, fel Jacob Epstein, Eric Gill a Henri Gaudier-Breszka. Roedd yn well ganddyn nhw gerfio calchfaen feddalach a llai dwys, Carreg Portland a thywodfaen.