Transcript (en)

This guy decided to split the frozen lava to create the sharpest knife in the world. First, he had to find an active volcano, from which red-hot magma flows. Then, he collected this magma, and cooled it at a rate of 100 degrees per second. The result is a solidified piece of lava, which is called obsidian or volcanic glass. A piece of glass like this is 16 times sharper than any surgical scalpel. After that, the guy began to carefully chip off the extra pieces to form a thin blank for the future blade. Then he shaped the workpiece into a knife and carefully ground it. The output turned out to be a real work of art. This knife is so dangerous that it is not recommended to take it with your bare hands. The sharpness of the blade is enough to cut vegetables into the thinnest slices, and it cuts meat literally like butter. Due to the very high complexity of manufacturing, such knives cost from $400.