Obsidian Tianmu-Obsidian Tianmu is extremely difficult to fire and needs tens of thousands of firings to succeed. It is the national treasure of the Song Dynasty. In ancient times, a top-class Tianmu lamp was priceless. The production technology of Obsidian Tianmu has long been lost in China. At present, there are only four Tianmu tea bowls in Song Dynasty in Japan.
Seismograph-The waiting seismograph invented by Zhang Heng, what people see now is copied according to the shape. The real appearance in history, internal structure and principle have long been impossible to research and have not been completely restored.
At the end of the Spring and Autumn Period, the bronze sword of Yue State —— Hook Jian Peijun Sword, remains as good as new after being unearthed for more than 2,000 years. This sword is exquisitely made and uses composite metal technology. At that time, the anti-corrosion and anti-rust technology was also a must. It was still sharp and cold when it was unearthed. Even now, it is impossible to copy this technology perfectly.
Mountain armor-a kind of China armor, appeared in the Tang Dynasty. At that time, due to the complicated production and high cost, it was generally the armor of senior generals. Mountain armor perfectly combines the strength of plate armor with the flexibility of chain armor. Ancient murals in China often appear, but no real objects have been unearthed. Its armor is mostly composed of herringbone metal plates, so it is called mountain armor.
Mafeisan-It is said that the prescription of Mafeisan, an oral anesthetic created by Hua Tuo and used for surgery, has long been lost. Later generations have been copying with reference to ancient books, but they have not met the requirements of anesthesia surgery.
Caihou paper is an ancient paper-making technology, which is gradually lost because of its complex technology and high cost. Hundreds of processes of Cai Hou Paper are basically completed by manpower. It is said that this kind of paper does not fade for painting and writing, and it is thin and tough. It can be preserved as good as new for a hundred years, and cooked food will not rot and taste when wrapped in this paper for several days.