A system is presented whereby volcanic rocks may be classified chemically as follows:I. Subalkaline Rocks:A. Tholeiitic basalt series:Tholeiitic picrite-basalt; tholeiite; tholeiitic andesite.B. Calc-alkali series:High-alumina basalt; andesite; dacite; rhyolite.II. Alkaline Rocks:A. Alkali olivine basalt series:(1) Alkalic picrite–basalt; ankaramite; alkali basalt; hawaiite; mugearite; benmorite; trachyte.(2) Alkalic picrite–basalt; ankaramite; alkali basalt; trachybasalt; tristanite; trachyte.B. Nephelinic, leucitic, and analcitic rocks.III. Peralkaline Rocks:pantellerite, commendite, etc.

A Guide to the Chemical Classification of the Common Volcanic Rocks

Dissimilatory Fe(III) and Mn(IV) reduction.

Oxide pyrochlores — A review

II. Structure of Perovskites 1982 A. Crystal Structure 1982 B. Nonstoichiometry in Perovskites 1983 1. Oxygen Nonstoichiometry 1983 2. Cation Nonstoichiometry 1984 C. Physical Properties 1985 D. Adsorption Properties 1986 1. CO and NO Adsorption 1986 2. Oxygen Adsorption 1987 E. Specific Surface and Porosity 1987 F. Thermal Stability in a Reducing Atmosphere 1989 III. Acid−Base and Redox Properties 1990 A. Acidity and Basicity 1990 B. Redox Processes 1991 1. Kinetics and Mechanisms 1992 2. Reduction−Oxidation Cycles 1993 C. Ion Mobility 1993 1. Oxygen Transport 1993 2. Cation Transport 1994 IV. Heterogeneous Catalysis 1995 A. Oxidation Reactions 1995 1. CO Oxidation 1995 2. Oxidation of Hydrocarbons 1996 B. Pollution Abatement 2001 1. NOx Decomposition 2001 2. Exhaust Treatment 2002 3. Stability 2004 C. Hydrogenation and Hydrogenolysis Reactions 2004 1. Hydrogenation of Carbon Oxides 2004 2. Hydrogenation and Hydrogenolysis Reactions 2006

Chemical structures and performance of perovskite oxides.

Physical, chemical and electrochemical properties of pure and doped ceria

Solubility of sulfur in some magmas at 1 atmosphere

When the pH of a reaction mixture of γ-FeO(OH) and the iron(II) ion is raised from 5 to 9, the γ-FeO(OH) is transformed to stoicheiometric Fe3O4 at 25 °C. The transformation reaction is triggered by the adsorption of the iron(II) ion on γ-FeO(OH) at a pH above 7.3, and the adsorbed FeII–γ-FeO(OH) is subsequently transformed to Fe3O4. In each step, one proton is released, a total of two protons being released in the reaction. The reaction of the transformation step is written as follows: [γ-FeO(OH)]2FeOH+→ Fe3O4+ H2O + H+ and includes a dissolution–precipitation process. The adsorption of iron(II) ion on Fe3O4 seems to take place along with the formation of the intermediate by the adsorption of iron(II) ion on γ-FeO(OH).

Transformation of -FeO(OH) to Fe3O4 by adsorption of iron(II) ion on -FeO(OH)

A series of solid solution xTiFe2O4.·(1-x) Fe3O4 was synthesized by ceramic method over a whole range of the composition, 1≥x≥0. Changes of the Curie point, saturation moment and the lattice parameter with the composition were examined. Generalized titanomagnetite having some vacant site in the structure normally occupied in a spinel was also prepared by oxidizing the TiFe2O4-Fe3O4 solid solution series. The region within which the spinel structure can be in existence as a single phase was settled in a FeO-Fe2O3-TiO2 system. An equal lattice parameter line, equal Curie point line and equal saturation moment line for the generalized titanomagnetite were drawn on the FeO-Fe2O3-TiO2 system.

https://www.jstage.jst.go.jp/article/jgg1949/9/4/9_4_165/_pdf

Magnetic Properties of TiFe2O4-Fe3O4 System and Their Change with Oxidation

The olivine-spinel transition curve has been determined over the temperature range 700 to 1200°C in the pressure range 40 to 70 kb for Fe2SiO4 and 700 to 1500°C in the pressure range 20 to 40 kb for Ni2SiO4 by means of a tetrahedral-anvil type of high-pressure apparatus. For both silicates the transition has proved to be reversible within the precision of pressure and temperature measurements. The equation for the transition curve was determined to be P = 12 + 0.045T for Fe2SiO4 and P = 19 + 0.012T for Ni2SiO4, respectively, where P is in kilobars and T is in degrees centigrade. On the basis of these equations, the standard free energy of formation of spinel from olivine was calculated to be 4.6T (cal/mole) for Fe2SiO4 and 1200 + 0.98T (cal/mole) for Ni2SiO4, respectively, where T is absolute temperature.

Takashi Katsura

Papers

Solubility of sulfur in some magmas at 1 atmosphere

Transformation of -FeO(OH) to Fe3O4 by adsorption of iron(II) ion on -FeO(OH)

Magnetic Properties of TiFe2O4-Fe3O4 System and Their Change with Oxidation

The olivine-spinel transition in Fe2SiO4 and Ni2SiO4

Standard free energy of formation of YFeO3, Y3Fe5O12, and a new compound YFe2O4 in the FeFe2O3Y2O3 system at 1200°C