The truth about white 'flowers' blooming under the microscope of the terracotta army

50 years ago, the discovery of the Statue of Qin Shi Huang (or Terracotta Army) shocked the world when a life-sized Qin army from more than 2,000 years ago stepped off the ground in an unusual formation. Invincible lined up neatly, dignified and lifelike.

Yuan Zhong , 87 years old this year, was the leader of the archaeological team during the excavation of the Qin Shi Huang Soldier and Horse Statue, so he was honored by Chinese historical and archaeological circles as the "Father of the Terracotta Army". 

Yuan Zhong once said he would never forget the moments of bringing more than 8,000 terracotta warriors and horses buried underground for thousands of years to the surface. All have left deep and unforgettable memories for the archaeologists participating in the excavation process.

Photo: J. Arpon

Spring 1974. This is the busy farming season in Tay Duong village in Shaanxi province, China. To fight the drought, the villagers decided to dig a well several meters deep. By chance, pieces of ceramic statues appeared at the bottom of the well.

A few months later, the news reached the Shaanxi Provincial Cultural Relics Bureau, who immediately sent Yuan Zhong to lead an archaeological team to Tay Duong village to conduct excavations. As a result, they discovered terracotta warriors and horses that shocked the world.

Qin Shi Huang's terracotta army faced the three biggest "enemies".

When the Terracotta Horses first appeared, they were all full of gorgeous colors: vermillion red, purple red, pink blue, purple pink, black and other colors. However, these vivid colors disappear quickly after only 15 seconds .

"The incident made the entire archaeological team only have time to exclaim in surprise but not be able to take a camera in time to take pictures of the most intact and colorful statues " - The archaeological team members remember that moment regretfully. .

The vivid colors on the statue of Qin Shi Huang's soldiers and horses disappeared after 15 minutes, surprising the archaeological team.

According to historical records, the colors on Qin Shi Huang's terracotta warriors and horses were specially treated. Before firing, the sculptors applied a layer of rough paint to the surface, which can adhere and highlight the color after firing. The second layer of paint will make the colors more vivid and durable, helping thousands of statues not fade even when buried underground for more than 2,000 years.

Today, more than 1,000 terracotta warriors and horses are displayed in Pit No. 1 of the Qin Shi Huang Soldier and Horse Statue, but currently the paint color of all statues here has changed to black and gray.

For museum experts, the colors on the terracotta warriors and horses were lost forever and could not be restored.

And yet, conservation work today still faces huge challenges.

Researchers believe that environmental changes, microorganisms and dissolved salts are three major enemies that are gradually eroding the Qin Shi Huang Horse Statues.

Environmental changes are the main cause of the Terracotta Warriors fading and corroding, but microorganisms and dissolved salts cause the most damage. If you put terracotta warriors and horses under an electron microscope, you will see white 'flowers' blooming on their surfaces.

Experts believe that these white 'flowers' are mold spores widely present in the air. If exposed to the right temperature and humidity, they will grow quickly.

Mold spores on Qin Shi Huang's soldiers and horses statues. (Photo: Sohu).

When growing, these mold spores will secrete a large amount of pigments and acid-base substances. If they remain on the surface of the terracotta warriors and horses for a long time, they will slowly corrode the inside of the terracotta warriors and cause irreparable damage.

Although the museum has now limited the number of visitors and regularly cleans the surfaces of terracotta warriors and horses, it still cannot completely limit the damage caused by mold.

Every time he visits the Qin Shi Huang Terracotta Warriors and Horses Museum, Mr. Yuan Zhong feels regretful, thinking that he made a big mistake during the excavation process. Because of that, he was just trying to dig up underground cultural relics without clearly realizing that the humidity and temperature underground were different from those on the ground.

This is what the "Father of the Terracotta Army" felt most tormented and regretted when participating in the excavation of one of the world's massive monuments.

Currently, China continues the process of searching and finding relics in this area with more modern technological equipment to preserve as many soldier and horse statues as possible.