Satterlyite is hydroxyl bearing iron phosphate with a space group P31m. The structure of satterlyite is made up of two pairs of face shared, distorted octahedra, the two faces are linked together by sharing edges to form double chains along the [001] plain. The double chains share ligands with six other double chains to make a 3D network holding three tetrahedra, linked by the corners to the octahedra (Kolitsch, 2002). The two oOctahedra have different occupancies; the Fe to Mg ratio of the M sites are 0.838(2):0.162(2) for the M(1) site and 0.706(2):0.294(2) for the M(2) site (Kolitsch, 2002). The structure contains three H atoms; two are share ligands with two octahedra and the third strongly disordered H atom is bonded to O of the tetrahedron (Kolitsch, 2002).
Holtedahlite, a mineral that was found in Tingelstadtjern quarry in Norway, with the formula is isostructural with satterlyite (Raade, 1979).
Infrared absorption powder spectra show that satterlyite is different from natural haltedahlite in that there is no carbonate for phosphate substitution (Kolitsch, 2002). Satterlyite is also structurally related to
phosphoellenbergerite, a mineral that was discovered in Modum, Norway; near San Giocomo Vallone Di Gilba, in Western Alps of Italy (Palache, 1951); the minerals formula is (Kolitsch, 2002). Electron paramagnetic resonance and
optical absorption studies have investigated the iron phosphate mineral satterlyite and
gormanite. Results of the optical studies show that both minerals have
ferrous and
ferric ions (Chandrasekhar, 2003). These studies also show that the site symmetry of Fe(III) in satterlyite is tetragonally distorted. However, the Fe(II) ions is tetragonally distorted octahedral (Chandrasekhar, 2003). The complex structure of satterlyite is made up of two pairs of face shared, distorted octahedra, linked together by sharing edges to form double chains along [001]. ==Physical properties==