Skip to Main Content
Skip Nav Destination

The staurolite structure is based upon an approximately cubic close packed array of oxygens with mainly (Al,Fe,Mg) in its octahedral and (Si,Al,Fe) in its tetrahedral interstices. It can be described also in terms of (010) slabs of the kyanite (Al2SiO5) structure alternating with layers of cations in octahedral and tetrahedral coordination with basic composition AlFe2O3(OH), but capable of exhibiting a wide range of cation substitutions (see below). The two components are labelled K and S, respectively, in Fig. 31. In the S layer the Al octahedra share edges forming chains parallel to the z axis. The ideal overall formula for staurolite is H2Fe2+4Al18Si8O48 but analysed staurolites contain between 2 and 4 hydrogens per formula unit. This would result in a net positive charge, but it is balanced by substitutions such as Al for Si, or Mg,Fe2+ for Al and also by only partial occupation of some cation sites. A different view of the staurolite structure is that given by the polyhedral model shown in perspective in Fig 32.

You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Close Modal

or Create an Account

Close Modal
Close Modal