Natural graphite (otherwise known as plumbago or black lead) is a variety of carbon distinguished by its lustre and its property of marking paper (for which reason it is used as pencil lead). Its apparent specific gravity varies, according to its degree of purity, between 1.9 and 2.26; the carbon content of the purest grades ranges from 90 to 96 %, while the cheaper grades contain only 40 to 80 %.
Natural graphite remains in this heading when it has been heat treated merely to remove impurities. Apart from its use in pencils, natural graphite is also used as a polish, for the manufacture of crucibles and other refractory articles, furnace electrodes and other electric parts. The heading excludes artificial graphite (which closely resembles natural graphite but has a higher degree of purity and lower specific gravity), colloidal or semi‑colloidal graphite and preparations based on graphite in the form of pastes, blocks, plates and other semi‑manufactures (heading 38.01). It also excludes articles of natural graphite (usually heading 68.15, 69.02, 69.03 or 85.45).
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