Few ancient paintings painted with pigments can be preserved so far, and all we see are ink paintings. National treasures are painted with pigments, and we can still see the luster of its bright pigments until now. This painting was made by Wang Ximeng, a painter in the Northern Song Dynasty, and it has a history of more than 900 years. But now we can see that its luster is still bright. Why hasn't it faded? Pigments are generally divided into plant pigments and mineral pigments. Plant pigments are very easy to fade, and the original color cannot be seen in three to five years, while mineral raw materials will not fade for thousands of years. "A Thousand Miles Map" is painted with mineral raw materials, and not with ordinary mineral raw materials, but with the best gem pigments.

The guests of the national treasure once said that the best gems are used for painting and the second-class gems are used for jewelry works. The map of a thousand miles across the country is made of the best gem pigments. The color of this painting is mainly composed of blue and green. We can see that the nearby hills are green and the distant hills are blue pigments. The raw materials for extracting turquoise pigment are azurite and malachite. Blue copper ore can be used to extract copper like copper ore, and can also be used as blue pigment. Blue copper ore is not as durable as precious stones, its hardness is low, and its color soon disappears. Usually make brooches or beads. Malachite is relatively rare, and is regarded as a sacred stone by Indians, which has the function of exorcism. It is actually an ancient jade, and Wang Ximeng uses this malachite with low hardness to color it.

Although mineral pigments are not easy to fade, they are easy to fall off, so they are generally not displayed. Some paint will fall off at every exhibition. Since its completion 60 years ago, the Forbidden City has only been exhibited four times, and visitors are required to watch this painting for no more than five minutes. If you look at this painting carefully, you will find that it reflects the unique luster of gems.