Celadon
stoneware dish, fluted, blue celadon
Celadon is the name given to a family of glazes that developed over a long period of time in China, reaching its zenith in the work produced during the Song dynasty. The glaze colour ranges from soft blue through to strong green (but never bright green). It is usually a very quiet, subdued glaze, with great depth due to minute bubble development; sometimes soft and luminous and in others it can be bright and transparent.
Celadon is usually a \'stiff\' glaze, that is, not very fluid; the colour is due to a small amount of iron in the ingredients, either from an irony clay or rock. The Chinese potters used a \'glaze-stone\', which we would call a soft micaceous rock. The schist I use from \'Blue Biddy\' near Gulgong is a similar material.
The name \'Celadon\' is an historical anomaly; it appears to be a French name that has its origins in a play popular in 17th. century Paris....a pastoral romance, \'l\'Astree\', by the playwright Honore d\'Urfe. The principal character in the play, named Celadon, appeared in a jade green cape. Gompertz also alludes to a reference in the seventh book of Homer\'s Iliad to the Greek river of the same name: \'where Celadon rolls down his rapid tide\'....the Chinese, of course, have no such origin, and simply refer to all glazes of this blue/green family as ching zu (\'greenware\')..
The Chinese valued their celadon wares primarily through the resemblance of the varied glazes to jade, and also because of the superb technical accomplishment that they embodied. Poets waxed lyrical about their beauty as in this verse by the Tang poet Xu Yin:
Like bright moons cunningly carved and dyed with spring water:
Like curling discs of thinnest ice, filled with green clouds:
Like ancient moss-eaten bronze mirrors lying on the mat:
Like tender lotus leaves full of dewdrops floating on the river-side.
(Bushell\'s translation)
The Chinese celadons can be roughly divided into those from north and south; the \'Northern celadons\' are characterised by a darker, more olive toned green glaze (the kilns were often fired with coal, and prone to partial oxidisation) which was thinner and more fluid than the southern types: the pots usually featured elaborately carved decoration which was enhanced by the transparent glaze. The southern glazes were softer, more opaque, usually thicker and of more subdued tones of green and blue. Carving was less often used. These pots not only reflected a different sensibility, but were a clear product of a change in available raw materials and the use of wood as a fuel in the kilns.
Modern Celadon
As a glaze type, Celadon has continued to be made in China since the Song Dynasty. With the fall of the Dynasty and the emergence of the Ming rulers, most of the Celadon we would be familiar with in the west was made in Jingdezhen; though not of the same luminous quality as the best of Longquan, a typical Ming dish displays a glaze of sea-green colour and some opacity, depending on firing temperature...whereas the typical glazes of the following Dynasty, the Qing, tended to be thinner, more transparent and of different green hues. Jingdezhen again was probably the largest centre of production, but good Celadons were produced in far ranging areas of China. This is still the case today, and modern Chinese celadon resembles its Qing antecedents more closely than any other. Looking at the glaze buckets in a modern Chinese factory, whether in the north or south, reveals the typical pink colour we would see in most studios in the west using celadon, or in any teaching institution; that pink coming from the addition of a small amount of Iron Oxide (Fe2O3) added to otherwise white firing ingredients.
In the search for the highest possible quality of glaze, it is my opinion that this is more achievable using materials where the iron is intimately bound up in the crystal structure of the material, whether it be clay or rock. The Sung Chinese would most likely have used a slightly iron stained clay, as the work was raw glazed and once fired (requiring a higher clay content in the glaze). In my work I fire twice, i.e. with a biscuit firing first, and I have found that I can obtain better results using a fusible rock source, such as an irony schist or shale; this is only possible if you have ball-milling equipment to grind the material and then the glaze. Milling the glaze for a number of hours is an important stage in producing good quality glazes.