Sword of Goujian

The Sword of Goujian (Traditional Chinese: 越王勾踐劍, Simplified Chinese: 越王勾践剑) is an archaeological artifact of the Spring and Autumn Period (771 to 403 BCE) found in 1965 in Hubei, China. Renowned for its sharpness and resistance to tarnish, this historical artifact of ancient China is currently in the possession of the Hubei Provincial Museum.

Discovery
In 1965, while an archaeological survey was being performed along the second main aqueduct of the Zhang River Reservoir in Jingzhou, Hubei, more than fifty ancient tombs of the Chu State were found in Jiangling County. The dig started in the middle of October 1965 and ended in January 1966.

More than 2,000 artifacts were recovered from the sites, including a bronze sword. In December 1965, 7 km from the ruins of Jinan, an ancient capital of Chu, a casket was discovered at Wangshan site #1. Inside, an ornate bronze sword was found with a human skeleton.

The sword was found sheathed in a wooden scabbard finished in black lacquer. The scabbard had an almost air-tight fit with the sword body. Unsheathing the sword revealed an untarnished blade, despite the tomb being soaked in underground water for over 2,000 years.

Identification
On one side of the blade, two columns of text are visible. Eight characters are written in an ancient script. The script was found to be Bird-worm seal script (literally "birds and worms characters" owing to the intricate decorations of the defining strokes), a variant of seal script. Initial analysis of the text deciphered six of the characters, "King of Yue" (越王) and "made this sword for [his] personal use" (自作用剑).

The remaining two characters were likely the name of this King of Yue. From its origin in 510 BCE to its demise at the hands of Chu in 334 BCE, nine kings ruled Yue, including Goujian, Lu Cheng, Bu Shou, Zhu Gou, and others. The identity of this king sparked debate among archeologists and Chinese language scholars. The discussion was carried out mostly in letters, and it involved famous scholars such as Guo Moruo. After more than two months, the experts started to form a consensus that the original owner of the sword was Goujian, the King of Yue made famous by his perseverance in time of hardship. So the entirety of the text reads "[Belonging to] King Goujian of Yue, made for [his] personal use" (越王勾践 自作用劍).

Construction
The sword of Goujian is 55.6 cm in length, including a 8.4 cm hilt; the blade is 4.6 cm wide at its base. The sword weighs 875 g. In addition to the repeating dark rhombi pattern on both sides of the blade, there are decorations of blue crystals and turquoise. The grip of the sword is bound by silk, while the pommel is composed of eleven concentric circles.

Chemical composition
The Sword of Goujian still has a sharp blade and shows no signs of tarnish. To understand why, scientists at Fudan University and CAS used modern equipment to determine the chemical composition of the sword, as shown in the table below.

Amount of element by percentage
The body of the blade is mainly made of copper, making it more pliant and less likely to shatter; the edges have more tin content, making them harder and capable of retaining a sharper edge; the sulfur decreases the chance of tarnish in the patterns.

It is likely that the chemical composition, along with the almost air-tight scabbard, led to the exceptional state of preservation.