Faded wonders
In First Qin Emperor's Mausoleum Museum, pit 1, at 260 square kilometers, is the largest and most impressive. It yields over 1,000 warriors and horses, all facing east in a rectangular array in solemn ash black, which is the color that most people know about the Qin Dynasty (221BC-206BC) and see in their pictures.
For archeologists, the excavation and preservation of the Terracotta Warriors are the two major problems. Changes in the environment are the main cause of the rapid color fading of figures while their preservation is confronted with micro-organisms and soluble salt.
Mold spores that exist extensively in the air and earth grow rapidly when temperatures and humidity are appropriate. Some mold growth can secrete pigments and produce acid or other harmful substances, deposited on the surface of clay figures, causing damages to the treasure relics.
Meanwhile, a layer of frosty soluble salt is congealed on the clay surface, leading to irreversible damage. A slight change in temperature and humidity would result in the repeated coagulation and dissolution of the soluble salt, enlarging the interspace in the sculpture and lowering their strength. Even a gentle touch will cause the surface to flake like a crispy biscuit.
"Environmental change, micro-organisms and soluble salt are what archeologists have identified as culprits to the discoloring of Terracotta Warriors," Xia said. "The temperature and humidity underground function as the shield of the figures' colors. Once unearthed, the surface quickly dehydrated and flaked off, which is truly regrettable. When we first discovered the Terracotta Warriors, we were not able to preserve the colors of the figures at that time."
Power of science and technology
Since the 1980s, Chinese and foreign scientists have carried out collaborative research on preservation of the Terracotta Warriors and their original colors. Breakthroughs have been made.
According to the president of the First Qin Emperor's Mausoleum Museum, Hou Ningbin, Chinese researchers have worked with experts from the Bavarian State Conservation Office in Germany since 1990s and have found a method to treat the surface with an emulsion of polyurethane and polyethylene glycol.
The preservative, known as PEG, helps save the figures' colors. During the recent excavation, archeologists sprayed the exposed parts with PEG the moment a painted figure was unearthed, then wrapped it with a plastic film to keep the humidity. The most colorful pieces were moved together with the surrounding earth to an on-site lab for further treatment.
The museum also established five special labs including a scanning electron microscope lab, a microbiology lab, a microscopic analysis lab, a colored cultural relics preservation lab and a comprehensive restoration lab. To everyone's delight, the modern techniques for preserving ancient colors have proved to be working.
"The new color preservation technique can help keep the original colors for at least 10 years," says Xia.
With the rapid development of modern science and technology, they are able to keep the Terracotta Warrior's true colors. With the deepening of research, experts also found that the Qin people had very sophisticated methods of utilizing colors. But there are still unsolved mysteries.
Unsolved mysteries
According to The Basic Annals of First Qin Emperor in Shiji, after the First Emperor's annexation of the six kingdoms following protracted wars, the color black was believed to be the most exalted color.
According to statistics, Terracotta Warriors are pale green, red, crimson, pink, sky blue, white, ochre and other colors, from which four colors - green, red, pink purple and sky blue - are the most popular. Does this finding contradict the record of "the Qin exalted black"?
"Colors are advocated differently in different dynasties in Chinese history. Color usage is related to folklore and culture. Some say that Qin advocated black, but the Terracotta Warriors show that Qin actually might have advocated many colors," Hou said.
"More types of colors and more vivid colors are used on the generals; the regular warriors have few colors and sometimes only show a simple paint, showing the concept of 'class' during the Qin Dynasty," he added.
"We divided the Terracotta Warriors into four levels. There are only nine generals, and their use of color is very complex and extremely delicate," Hou said. For intermediate and lower-ranking military officer figures and commonplace soldiers' figures, the use of color is relatively simple.
A kneeling figure, that has relatively good preservation of color, reflects that the Terracotta Warriors had very colorful clothes: he is clad in a pale green long jacket, ochre armor and the armor covered with red belts and white nails, with lower body in blue pants and purple gaiters.
Yuan believes there were both exalted colors and popular colors in ancient clothing. Exalted colors reflected the characteristics of the era and politics, with black used for a sacrifice, daily meetings and other national events while popular colors were used for daily cloths among the public.
"The colors of the Terracotta Warriors fully display the liveliness of the Qin people. It is definitely not that everyone wore black just because Qin exalted black, neither did they show sadness or low spirit," says Yuan.
"We have only excavated 1 percent of the total mausoleum. Since our technological methods are limited, with many unpredictable factors, we'd rather keep them buried," Hou said.
"It will take hundreds of years or even longer to fully reveal those colorful mysteries to the public," he said.
