A Brief Talk on “Iron Spot” of Yuan Blue and White Porcelain

The bulk of the pigment used in the original blue-and-white porcelain pattern, that is, because of the impurity in the pigment, the impurity and pigment particles in the firing are often aggregated to form a strip or spot-like accumulation of green (or as a condensation spot, that is, the dark black patch that appears in the color of the blue-and-white flowers, the speckle band), If the impurity content at the accumulation of blue reached a critical value, it will precipitate a very small spot-like crystal, known as the crystal spot, commonly known as” iron spot. “”Iron spot” phenomenon in the book is very simple, for example, “ancient Chinese porcelain appreciation” said: “Yuan Qinghua Su materials, imported materials, glaze black iron spots.””The blue-and-white paintings imported from the Yuan Dynasty are richly decorated… with black-and-brown spots.” That’s all.

As for the observation of the shape of “iron spot”, to identify the property of objects or the reliability of the true and false, the present research shows that it can only provide reference for the appropriate, can not be like Yuan blue and white porcelain other components, such as pigments, soil, enamel, painting style, The judgment of process form and so on plays a decisive role.

In addition, not all the blue-and-white porcelain will appear “iron spot”, especially some of the most beautiful tools do not have “iron spot”, and some of the blue-and-white porcelain objects” iron spot “very little, need to use a magnifying glass to observe.No “iron spot” artifacts are also the Yuan Dynasty in the pursuit of perfection in the process of the fundamental goal, so it is not appropriate to have “iron spot” to do the only true or false basis.This is what we should have in mind when we say “iron spot”.

We talk about objects with “iron spots” which are generally divided into two categories.A variety of utensils represented by imports of Subryni Qinggu materials (or translated as Su Ni Bo Qing, Su Ma Li Qing, Su Lai Ma Ni, English Soleimani, etc., are all one thing).Another kind is to import and home-made goods after mixing as a representative of the utensils.

Imported Su Boni Qinggu material “iron spot” formation is because of impurities containing iron, domestic materials because of impurities in manganese content, so called “iron spot” is not appropriate, but at present there is no direct call “manganese spot”, but still all called “iron spot”, Including the import and domestic mix of “iron”, “manganese” mixed spots are also known as” iron “.This can only be regarded as a title, everyone’s habit just.

Here, we must understand the relationship between “iron spot” and the accumulation of green spot (condensation spot), “iron spot” is formed on the basis of the accumulation of green, that is, the accumulation of green is a prerequisite.Where there is no accumulation of green, there is no “iron spot.”The accumulation of green is a kind of condensation out of the hair black spot, and “iron spot” is from this accumulation of black color in the precipitation of the crystal-like metal spots.This metal-containing spot is based on the former, which is the former reaction.The crystal’s metallic plaque is chemical not only of “iron” or “manganese” but also of many other elements (iron is iron oxide and manganese is manganese oxide).

The value of “Iron Spot” is that it can be judged by its different shape and color of the reference opinions.But “iron spot” phenomenon is very complex, size, shape, color are varied.Each device is different from each other.If it is not really master its key characteristics, it is easy to draw a mistake to cover the whole, that is, to “iron spot” point to deny the whole, especially in the main features of the artifacts are consistent with the circumstances, such as pigments, glaze, tire soil, processing the shape of all characters, The result of not looking at “iron spot” to implement a bit of denial, such a result is unfair, also can not be trusted.Therefore, it is necessary for us to re-explain the reference factors of this sensitivity.

1. Iron Spot Shape:

1. Deformation point, block.There are single-point, multi-point, aggregation point.No matter single, many or aggregated, all are irregular round, block or irregular multi-point interlacing beach lines.Its edges are rough or more rounded.Size diameters in 1 mm to 2 mm or larger.

2. A long strip of deformation.Long, short, direction along with the accumulation of blue to condense the dark black color trend or vertical or horizontal or oblique, irregular or rough edges.3 to 5 mm long, or more elongated, or point-like arrangement of growth bars and other more complex forms.

3. Dispersed silk.Under 40 times magnifying glass, show like spider silk structure lines, some like silk net lines, or chaotic change silk lines, or dot-like, strip-like added silk net lines, or point-like mixed plus silk lines.

4. Volcanic pits.A crater-like shape formed after a break in the center of a point or block, in which a small crater is formed and a circle is trapped in a glaze (with a root) called a volcanic spot.

5. Smaller spots.A very small spot that requires a 40-fold magnifying glass to be visible.The quantity of “iron spot” of Yuan blue-and-white porcelain varies with the fineness or firing of the ware. In general, the fine ware “iron spot”, which is imported or mainly imported, tends to be less and tends to be smaller. The “iron spot” tends to be larger and larger.

2. Iron Spot Color:

The impurity in the imported stock is mainly ferric oxide, while the impurity in the domestic stock is mainly manganese oxide, so the color of iron spot is different after the crystal is formed.

1. Imported “iron spot” is dark black, black gray, gray or color brownish, brown is not heavy, when we look at the Su material, its” iron spot “color more dark the more pure material.General “iron spot” hidden in the dark in the accumulation of green, we need to look carefully to find, and the purer Su material “iron spot” quantity is generally less.

2. The color of mixed and home-made materials is the most complex.Mixing selling materials refers to the import Subrini Qinggu materials mixed with domestic selling materials, but because of the different proportions, “iron spot” color changes more quantity will also tend to more.There are usually two kinds of situations: The first is that after the import selling material is mixed with the domestic selling material (at that time, most of them are high-yielding pebble Qinggu material in Ruizhou, Jiangxi Province, which turns dark and gray and contains more manganese), that is to say, the manganese oxide content increases. “Iron spot” color began to brown,40 times under the magnifying glass can be seen blue-brown, black-brown, gray-brown, yellow-brown and other characteristics of brown spots.Therefore, it is known that the brownish spots are the reaction after the content of manganese oxide is too high.This is the difference between pure imports of Suberney green grain.

In the second case, the “iron spot”, or “silver spot”, commonly referred to as” tin spot “, is apt to appear as” tin spot”, with a bright glow of tin or silver, Only when the ratio of ferric oxide in imported stock to manganese oxide in domestic stock is properly mixed can it occur.Not all objects produce spots of tin.

3. The main materials are similar to those of Subernal Blue, with more iron in them, and their “iron spots” are black, black, gray and so on.If mixed with appropriate domestic materials, will also be “tin light”, too much will be brown and no “tin light”.What needs to be explained here is to return green material to also belong to foreign material at that time.”Hui Qing is a great youth of the western region, and the beautiful are also known as Buddhas.” It can be seen that the western part of the Yuan Dynasty was not produced in the mainland.This kind of selling material in the Yuan Dynasty is also used more, is a kind of blue and purple and more colorful, grain slightly thinner than Su materials but later began to use Zhejiang materials a little thick, then quite valuable.

Its characteristic is as” Hui Qing Fu “in” Jiangxi Dazhi · Tao Shu “points out, then dispersive but do not receive.” That is to say, the color particle of Hui Qing material is easy to release, do not condense, therefore return green material mainly in the object pattern, agglomerate spot (accumulation green place) the expression is not strong, Pigment particles often appear a kind of drift state in the pattern, and there are no obvious bar-like condensed flow and mottled condensed flow.Therefore, it is different to look at the material of Hui Qing and see the material of Su Boni, especially the difference in the agglomerating characteristics of the two pigments in the firing process: one is aggregate, the other is dispersion or not.Therefore, the “iron spot” on the pattern of the material-based objects is more random precipitation.

During the Yuan Dynasty, it was also often adjusted by adding pebbles, because the pebbles were more agglomerated, so that the “scattered” could be properly aggregated.There are more of them, too.

III. Glaze application of Iron Spot:

1. During the firing process, some of the “iron spots” produced are lower than the glaze surface and sink to the glaze surface, which is called” eating the tire “phenomenon.

2. There are quite a few objects” iron spots” that are either sinking or not sinking.Not all “iron spots” sink, but quite a few float on the surface.For example, such as the big pot of Yuan Qinghua tangled branches and peony patterns in the collections of Baotou and Shanghai, it is the case that the Yuan blue-and-white porcelain pieces unearthed at the site of the Yuan Dynasty of Baotou Yanjialiang.At present, including some theorists, the auction house in the introduction often only emphasized the first sinking, while ignoring the second floating on the surface of the situation, obviously not comprehensive.

3. As has been said, a portion of the “iron spot” is shaped like a crater, with a concave circle of glaze rising from the top and a “root” at the bottom.This is caused by the non-uniform temperature control during firing, which is different from the very uniform condition of modern imitation temperature control.

Therefore, it is not appropriate to eat do not eat freckles, do not sink under the standard as a judge Huai, otherwise will cause great misdirection, this is to be repeated to let everyone know.

Imitation of a lot of artifacts” iron spot “can do sinking, imitation of the” spot “, mainly color is not like, all do a larger and exaggerated, similar to the tinted tin pipe burning out of the skin color, not black or brown, and fresh.

Through the above discussion, we should grasp the main points:

1. The accumulation of blue and white porcelain can produce “iron spots”, but not all of them have” iron spots”.

2. There is a difference between the color of the pure imported Su-Boni green grain and the mixed “iron spot”. The more pure Su-Boni green grain material, the darker the color of the iron spot, and the less the spot, the more difficult to find.The more domestic materials added, the more the trend of browning.

From this we can see that where the “iron spot” trend towards more browning trend of the obvious objects, in fact, has been mixed into other materials, especially domestic selling materials, but which kind of selling materials mainly or the proportion of the size of the problem.These include the blue-and-white porcelain products that we know to be preserved in Iran and Iraq, which were also processed at home, with varying materials, some fairly pure, but some of them plain-colored (as my friends recently concluded after a special visit).

3. Some eat tires, some still float on the glaze table, not all of them sink.I hope that the convenience of people to see the side can see such as Baotou Yuan blue-and-white porcelain pots and other collection of artifacts, to explain the doubt.

4. The less the iron spot, the smaller the object, the more well-crafted the device, but also there are no “iron spot” objects.

5, “iron spot” phenomenon should only be used for reference, is not the key to determine the properties of the blue-and-white porcelain.

For example, below:

The black spot “iron spot” in Su Boni’s green material accumulation, can be seen clearly by careful observation, and the overall situation of “iron spot” in Su’s material is less.

 

The dark strip of black iron “iron spots” in Subney’s stump, with very slight browns, can be seen with careful observation.

 

The appearance of brown “iron spot” on the glaze table at the accumulation point of Chinese-made stone green mixed with Su-materials

 

The gray-brown “iron spot” appeared at the place where the Chinese-made stone-green materials were mixed with the Su materials, and the quantity tends to be more.

 

A “tin spot” in which a certain proportion of other materials (non-pebble green material) are mixed.

 

The black-brown “iron spot” appears in the middle of the raw material of Chinese-made pebble green, which needs to be seen carefully.

 

“Volcanic spot” and ordinary brown “iron spot” appeared at the accumulation of green material (pebble green mainly).

 

The accumulation of “volcanic spots” and ordinary” tin spots” in a certain proportion of other materials (non-pebble green materials).

 

The “tin spot” occurs when a certain proportion of other materials (non-pebble green material) is mixed into the baking soda.

 

It is characterized by divergence and not coacervation, so its” iron spot “appeared at random in the deep part, and it was a foreign material in the western region in the Yuan Dynasty.The blue is purple.Particles are slightly finer than Su’s, but thicker than gravel and later Zhejiang’s.

 

The black ash-like “iron spot” in the recycled green material.

 

Ming Yongle period of domestic materials (mainly pebble blue) green accumulation of the brown “iron spot.”