Carbonaceous refractory materials carbon

PROP Soot is defined as a brown-to-black substance incidentally produced during the incomplete and uncontrolled combustion of any carbonaceous material. It is a mixture of colloidal carbon, organic tars, and refractory inorganics whose composition depends on combustion conditions. It is not unusual for the tarry component to account for more than 50 weight percent of the soot, particularly, when produced by inefficient combustion of coal or wood. Can be distinguished from carbon black on the basis of differences in physical and chemical properties. 

The primitive carbonaceous meteorites, which include the hydrated CI and CM meteorites and mostly-anhydrous meteorites such as the Allende CV meteorite [69], reach Earth from the asteroid belt between Mars and Jupiter. Asteroid reflectance properties display a remarkably systematic distribution as a function of heliocentric distance for asteroids in this belt, and hence meteorite types, with the most primitive ones located farthest from the sun. Asteroid hydration occurred when internal heating melted (water) ice that had co-accreted with dust, chondrules and refractory inclusions in the solar nebula. These asteroids form the IR spectroscopic C-class with clays, carbon and organics at the surface similar to CI and CM meteorite parent bodies [70]. They and the Allende CV parent body, which apparently did not accrete (much) ice, are from the same zone of the asteroid belt. Even more primitive asteroids closer to Jupiter still contain co-accreted ices, organic materials and silicate dust. They define the IR spectroscopic primitive (P)-and dark (D)-class [70] bodies that include comet nuclei and many near-Earth asteroids [10]. 

---