Graphite

Graphite is usually found in the United States as isolated crystals in marble or schist. In most cases these are not commercial deposits but they do hold some value to rock collectors. A big deposit would be of automatic commercial value due to the fact that most of the graphite here is imported from Madagascar and Ceylon. Given that most graphite crystals are so small in size they can only be seen under the glass and most of the tests for identification are done in a laboratory. The native color of graphite is black and if it is scratched on a piece of paper it leaves a mark that looks like a pencil mark. Graphite is soft and can be scratched with a fingernail. Graphite has a metallic luster to it, has a hardness of 1 to 2, and a specific gravity of 2.3. Graphite is a good conductor of electricity and it does not fuse at considerably high temperatures and neither does it burn easily.