Callister - An introduction - 8th edition

Chapter 12 Structures and
Properties of Ceramics
The illustrations arranged vertically on the left side of the page present the
structure of quartz (SiO 2 ) from three different dimensional perspectives. White
and red balls represent, respectively, silicon and oxygen atoms.
Top left: Schematic representation of the most basic structural unit for
quartz (as well as for all silicate materials). Each atom of silicon is bonded to and
surrounded by four oxygen atoms, whose centers are located at the corners of a
4
tetrahedron. Chemically this unit is represented as SiO .
Center left: Sketch of a unit cell for quartz, which is composed of several interconnected
SiO tetrahedra.
Bottom left: Schematic diagram showing a large number of interconnected
SiO
tetrahedra. The shape of this structure is characteristic of that adopted by a
4
4
4
4
4
single crystal of quartz.
Bottom right: Photograph of two single crystals
of quartz. Note that the shape of the large crystal
in the photograph resembles the shape of the structure
shown in the adjacent (bottom left) schematic
diagram. [Quartz images courtesy of Amir C. Akhavan
(www.quartzpage.de); photograph of the quartz
single crystals courtesy of Irocks.com.]
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