Sugar charcoal should not be confused with Coal candy.
Sugar charcoal is formed by the charring of cane sugar, which was repeatedly recrystallized to remove any organic impurities.[1] It is also prepared by the dehydration of sugar in the presence of concentrated sulfuric acid. Since sulfuric acid is a dehydrating agent, it absorbs water from the sugar and leaves behind black residue of carbon. It is the purest form of amorphous carbon.
Since sugar charcoal is a method of producing very pure carbon it is used to prepare artificial diamonds. When heated strongly at high temperature (3000-3500 °C) and high pressure, it is converted into an artificial diamond.
It is used as a reducing agent in the process of extraction of metals.
Sugar charcoal has decolourizing properties, which means it removes some dyes, such as methylene blue, from water.