What are the Definitions of
the Five Levels of Structure?
- Electronic/Bonding Structure: The number
and manner in which the outer shell (valence)
electrons are employed to form bonds.
- As an example, silicon (atomic number = 14)
has 4 valence electrons.
- Atomic/Molecular Structure: The nature
of the atoms/molecules/monomers that
constitute the building blocks of the material.
- For example, the "silica monomer" consists
of a single silicon atom, which is tetrahedrally
bonded to four oxygen atoms. The oxygen atoms
themselves are bonded to two silicon atoms.
- Crystal Structure: The periodic arrangement
of atoms/molecules/monomers in space. Silica is
- Tridymite has a hexagonal crystal structure
- Cristobalite has a cubic crystal structure
- Silica glass is amorphous.
- However, all forms of silica (including Quartz)
have the same monomeric structure.
- Microstructure: The size and distribution
of individual grains/phases/defects in a material.
- As an example, the microstructure of Sandstone consists
of quartz grains in a calcite matrix.
- Macrostructure: The shape/size of the body
e.g., the "cut" of an amethyst (quartz) gemstone.