Resources written by Chas McCaw for sixth form chemistry teaching and beyond.
General interest:
Graphite Buckminsterfullerene Ice White phosphorus Benzene Cyclohexane AdamantaneCubic:
Sodium Caesium chloride Polonium Copper Halite Fluorite Antifluorite Zinc blende DiamondNon-cubic:
Hexagonal:
Magnesium WurtziteTetragonal:
RutileTrigonal:
α-quartzTriclinic:
Copper(II) sulfateOrthorhombic:
α-SulfurMonoclinic:
β-SulfurTo go directly to the unit cell structure, click the link to page 3 below.
Rutile is the chief mineral of titanium dioxide. It is used as a white pigment and for the extraction of titanium, which is now carried out electrochemically by cathodic reduction in the FFC Cambridge Process, developed at Cambridge University between 1996 and 1997.
A fragment of the bulk structure of rutile is shown to the left. The oxide ions are red and the titaniums are silver-coloured.
In the structure on the left the relative size of the ions is to scale, and nearest-neighbour ions are virtually in contact. In future pages the ions will not be shown in contact as it obscures the internal structure of the lattice. Rather, they will be scaled to half their atomic radius, ie one eighth of their volume. In any case, the determination of ion size has its problems. What x-ray diffraction determines most accurately are the positions of the nuclei in the lattice.
Go to page 2 to look a different representation of rutile.