An amorphous carbon. It is a light, loose, and extremely fine black powder with a very large specific surface area, ranging from 10 to 3000 m²/g. It is produced by the incomplete combustion or thermal decomposition of organic substances (such as natural gas, heavy oil, fuel oil, etc.) under conditions of insufficient air. Its specific gravity is 1.8-2.1. Those made from natural gas are called "gas black," those made from oils are called "lamp black," and those made from acetylene are called "acetylene black." Additionally, there are "channel black" and "furnace black." Based on performance, carbon black can be classified into "reinforcing carbon black," "conductive carbon black," "wear-resistant carbon black," etc. It can be used as a black dye for manufacturing Chinese ink, printing ink, paint, etc., and also as a reinforcing agent for rubber.