4、地球物质的化学组成 Rock and Minerals inearth Identifying characteristics of Minerals 12. The two fundamental characteristics of a mineral that together distinguish it from all other minerals are its chemical composition and its crystal structure. No two minerals are identical in both respects, though they may be the same in one. For example, diamond and graphite(the"lead"in a lead pencil) are chemical the same--both are made up pure carbon. Their physical properties, however, are vastly different because of the differences in their internal crystalline structures. In a diamond, each carbon atom is firmly bonded to every adjacent carbon atom in every direction. In graphiteA 33, the carbon atoms are bonded strongly in two dimensions into sheets, but the sheets are only weakly held together in the third 环质 Environmental Geology环境地质学 Environmental Geology 4、地球物质的化学组成 Rock and Minerals in earth Identifying Characteristics of Minerals 12. The two fundamental characteristics of a mineral that together distinguish it from all other minerals are its chemical composition and its crystal structure. No two minerals are identical in both respects, though they may be the same in one. For example, diamond and graphite (the “lead” in a lead pencil) are chemical the same--both are made up pure carbon. Their physical properties, however, are vastly different because of the differences in their internal crystalline structures. In a diamond, each carbon atom is firmly bonded to every adjacent carbon atom in every direction. In graphite石墨, the carbon atoms are bonded strongly in two dimensions into sheets, but the sheets are only weakly held together in the third