acetylene black

A special type of carbon black formed by an exothermic decomposition of acetylene. It is characterized by the highest degree of aggregation and crystalline orientation when compared with all types of carbon black.
Acetylene black must not be confused with the carbon black produced as a by-product during the production of acetylene in the electric arc process.
PAC, 1995, 67, 473 (Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)) on page 476