Monday, 18 March 2013

Plate 8 - part I

After a long break, mostly due to guilt at not finishing the two plates that languish in my kitchen cupboard, I have started decorating plates again. This resurgence of interested was prompted by a post by Aliette of Stormhold quite a few months ago. She posted a rather nice plate (13th Century I think) that sported a simple cat motif. While looking for the details of the original I stumbled upon something much more interesting, a 12th century peacock dish from Syria (Figure 1).

Fig 1: Peacock plate from Syria. 12th Century. Accession number: 29.160.17. Metropolitan Museum of Art

The back of the dish is plain and shows minor green staining. Interestingly, when stood 'flat', the plate appears to slant towards the left of the peacock. The rainbow luster around the edge of the plate and around the breast of the peacock bothered me initially. In my limited knowledge of ceramics, I associate that effect with modern day fairies or ballerina ceramics, not 12th century dishes. Looking at the unstained head of the peacock where the plate is the whitest there is no iridescent coloration. So, the two most likely causes are 1. a pigment used to outline the peacock and add decoration to the edge of the dish as been changed to create the irridescence, 2. groundwater or whatever stained the dish orange transported chemicals onto the plate to create the irridescence.

Cause 1 - pigment conversion
I have sifted through the Met's Syrian 12th century ceramic collection and found a fragment of a bowl (Figure 2) featuring a bird which has a similar white outline of the wings and features to the peacock. Given there is no trace of a decorative motif on the rim of the peacock plate this suggests that the void around the wing was intentional not the result of alteration of pigment causing the iridescence.

Fig 2: Fragment of a bowl. late 12th - first half 13th century. Composite body, underglaze painted. Syria. Accession number: 1978.546.9 The swan (?) depicted has voids outlining it's primary leg and wing.

Cause 2 - pigment discoloration
I have examined the images of most of the Met's Syrian ceramic collection and have found others with the iridescent staining (Figure 3 and 4). Both plates feature blue and green images similar to the peacock in colour. The Faun? (Figure 4) has the best example of irridescence as it only appears on areas that also exhibit orange staining. The likely cause of the iridescence is groundwater interacting with the underglaze chemicals (copper?) and causing the staining.

Fig 3: Syrian (Raqqa) plate featuring a Sphinx. late 12th- first half 13th century. Made out of stonepaste, under-glaze painted under a transparent, greenish colorless glaze. Accession number: 13.219.1. Metropolitan Museum of Art.

Fig 4: Syrian (Raqqa) plate featuring a faun? Stonepaste, under-glaze painted. Accession number: 56.185.5. Metropolitan Museum of Art.

So. Having made the conclusion I can ignore the iridescence, I can now happily paint a white plate with a beautiful blue and green peacock.

Wednesday, 13 March 2013

Islamic Dragons

Document delivery via Monash University is a wonderful thing. You simply click on the book you want and they eventually deliver it to a library near you. Unfortunately it isn't always as quick as one would like. Take for example, todays book: The Dragon in Medieval East Christian and Islamic Art by Sara Kuehn (ISBN: 0929-2403 / 9789004186637). It arrived recently and I can't for the life of me remember why I had it. I suspect I ordered it because I was planning on entering an A&S competition that featured images of Wyvyrns and I wanted to find one that suited my persona.

Anyway, I've flipped through the collection of articles in this book and here are some of the best images for your consumption:

A winged dragon with forelegs. Buckle of a belt, Mongl Empire, Astrakhan region. Probably 13th century, Silver, gilding, inlay in a black substance (niello?) Length 6.3 cmm width 3.1 cm. St Petersburg Hermatiage, inv. no. SO-762 . (I really really like this one!)

Confronted pairs of winged dragon tailed dragons with forelegs. Detail from a candlestick base, the Jazira. Thirteenth century. Copper alloy, silver inlay. Metropolitian Museum of Art. Inv. no. 91.1.561.

 A musician with a dragon-headed stringed instrument. Wall painting. Panjikent (Tajikistan). 8th century. Dushanbe National Museum.

Confronted dragon-headed birds with interlaced necks. Missal, Armenia. 9th or 10th century. Ejmiatsin, State Library. MS 958 fol 10.

Wednesday, 6 March 2013

Leeching around

I've just come back from a week long field trip with JMSS. It was a lovely week with 10 exceptional year 10's. They hadn't done any geology before but they were quite interested and asked some great questions. We went to Buchan, toured the limestone caves and examined the fossils at potholes reserve. Buchan is a lovely little town. I've been there a number of times with the 2nd years and I can never get sick of going on the caves tour.

Stalactites and stalagmites in the Royal Cave, Buchan Reserve.

On the second day we drove to Inverloch and looked at the fossilized forest and the dinosaur dreaming fossil evacuation site. The dinosaur dreaming site is a world class fossil site where they've uncovered birds, mammals and even a Tyrant dinosaur. Jim found some beautiful examples of rip-up clasts and got all excited about them. Sedimentologists - go figure.

On day three we went to Yanakee then to Wilsons Prom and climbed Mt Oberon. The prom is a beautiful granitic batholith which has some lovely pink outcrops. We collected sand from Squeeky beach but more importantly, we got some mudstone samples the park rangers had used as road base. They feature a lovely green mineral (still to be identified, I'm holding out for variscite). Apparently they're from the Fish Creek Quarry, but this requires further investigation.

We finally went to Bendigo and took a tour of the Central Debora mine. The old workings are quite interesting and the honeycomb of tunnels under Bendigo are immense. Determining the best pumping methods to remove the arsenic tainted water would be a unique problem.
On the way home from Bendigo we stopped by Chewton to pan for gold. Unfortunately the creek was so low the water was stagnet and manky. Unfortunately for the students that is. Fortunately for me this left a beautiful refolded recumbent fold on view. I got very excited much to the amusement of the children. I took some photos and I plan on going back to do a proper survey.
As we were leaving one of the students called me over. She'd spotted a leech and knew I was interested in collecting them. She helped me hand catch it and in the process disturbed a larger one. We caught it, bottled them and now they sit on my kitchen table while I try and work out a more permanent home for them.  They're massive tiger leeches. I've caught them for my housemate to use in his presentations on Medieval Medicine at schools. They'll make great props and only have to be fed every 50-70 days.

Alpha is about 5" and Beta is about 2" - MASSIVE leeches.