石墨，一种质软、钢灰黑色、有金属光泽和滑腻感的碳的六方晶形的同素异构体，用于铅笔、滑润剂、颜料和涂层，可被制成多种形状，如模子、砖块、电极、坩埚和火箭发动机喷管

• a soft,steel-gray to black,hexagonally crystallized allotrope of carbon with a metallic luster and a greasy feel,used in lead pencils,lubricants,paints,and coatings,that is fabricated into a variety of forms such as molds,bricks,electrodes,crucibles,and rocket nozzles