Silicate solid solution series

SiO - TiO the oxide solid solution series MgO - FeO (magnesiowiistite), Mg TiO -Fe TiO (ulvospinel), MgTiO - FeTiO (geikielite - ilmenite) and MgTi Oj - FeTi O (karrooite - ferropseudobrookite = armalcolite) as well as the silicate solid solution series (Mg SiO - Fe SiO (olivine) and MgSiO - FeSi03 (pyroxene) are contained. 

Feldspar is a framework silicate in which tetrahedra containing A1 or Si are linked to one another by shared oxygens in all directions rather than in chains or sheets (3) The plagioclase solid-solution series... 

Alite is a solid-solution series of trigonal, monoclinic, and triclinic modifications of impure tricalcium silicate, which is generally termed C S in the cement industry. Substitution of magnesium and aluminum for silicon causes triclinic pseudotrigonal forms to change to monoclinic pseudotrigonal forms other substitutions may involve iron and sodium. Alite may include up to approximately 4 percent impurity (Ghosh, 1983). It comprises 40 to 70 percent of normal portland cement clinker. Its density is 3.13 to 3.22 Mg/m. ... 

Chemically, the chlorites are hydrous silicates incorporating medium-sized cations, primarily Mg, Al, and Fe, but occasionally Cr, Mn, Ni, V, Cu, and Li. There is a continuous solid solution series between the Mg and Fe varieties. Al substitutes for Si between the approximate limits 0.5 to 1.8 atoms per 4 tetrahedral positions. Most chlorites are trioctahedral and belong to the Mg-Fe series. Dioctahedral chlorites are rare, as are intermediate forms that combine one trioctahedral sheet with one dioctahedral sheet. 

Other portions of weathering profiles will establish, at any given point, an equilibrium between the fluid or aqueous solution and the silicate-oxide solids in the soil. Each portion of the profile will represent a different series of chemical conditions, i.e., the total relative masses of the various components will change with, for example, K O increasing downwards in the profile. However, the phase equilibria are such that the different portions of the profile can be analyzed on a P constant, T constant, X diagram for any small segment of the profile. 

A sodium aluminate solution (2.00 moles Al203/liter, 3.40 moles Na20/ liter, density 1.36 grams/ml) produced from hydrargillite was used as the alumina source in each series of tests. Silica was used as sodium silicate solution (5.98 moles Si02/liter, 1.77 moles Na20/liter, density 1.36 grams/ ml) and as solid amorphous silica with different surface areas (Table I). 

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