石墨为天然碳的三种形式的一种,是黑色至灰色的有光泽的矿物,莫氏硬度为2,比重1.9至2.25。石墨具有层状结构,底面的原子由六边形阵列的强共价键紧密地固定住,因此,石墨解理很好,但层间的键较弱,故使石墨具有较低的摩擦系数和有滑感。石墨又是一种很好的耐火材料,热膨胀系数低,在高导热材料中名列第五位。另外,石墨对于大多数的化学试剂具有化学惰性。在光学方面,石墨不透明,甚至对于 Graphite is one of three forms of natural carbon, a black to gray shiny mineral with a Mohs hardness of 2 and a specific gravity of 1.9 to 2.25. Graphite has a layered structure in which atoms on the underside are tightly held by a strong covalent bond of the hexagonal array so that the graphite cleaves very well but the bonds between the layers are weak so that the graphite has a lower coefficient of friction and There is a slippery feeling. Graphite, in turn, is a good refractory material with a low coefficient of thermal expansion and is the fifth highest thermal conductivity material. In addition, graphite is chemically inert to most chemicals. In optics, graphite is opaque even for