this is merely a collection of pictures, songs, articles, videos, and objects that i find interesting. all known sources are provided (i think). feel free to contribute with a citation or author/ artist if known. these are all things i just don't want to forget.
Monday, March 19, 2012
classes and classifications of coal
Coal is commonly classified according to rank and sulfur content. Rank is based on percentage of carbon (C) in coal and its heat when combusted.