Framework silicates form about 70% of the Earth’s crust, mainly feldspars ~50–60% and quartz ~10–15%. Less-abundant feldspathoids include nepheline-, leucite-, sodalite-group minerals, rich in structurally challenging properties. This review paper deals with anhydrous feldspar-, leucite/pollucite groups, emphasising importance parallel studies on natural synthetic samples. Four topics are cover...

The dissolution kinetics of silica-containing minerals in aggregates influences strongly the process ASR concrete. In this paper, effect different ions on rates SiO2 (amorphous and quartz) feldspars at high pH values was studied by following increase silicon concentrations experiments with a novel approach measuring evolution scratches polished surfaces. second method avoided problem precipitat...

Abstract In the first two papers of this series [Behrens, Phys Chem Minerals 48:8, 2021a; Behrens, 48:27, 2021b], incorporation hydrogen in feldspar structure, partitioning between feldspars and gases/fluids self-diffusion have been discussed, with particular focus on sanidine. Here, results reactions sanidine containing strongly bonded defects (Na,K)Cl are presented. Experiments were performed...

Heat capacities (5-380 K) have been measured by adiabatic calorimetry for five highly disordered alkali feldspars (AbeeOr1, Ab65Or15, Ab55Ora5, Ab25Ory5, and AblOree). Positive heat capacity deviations from a linear combination of the end-member heat capacities, which are present mostly at very low temperatures, result in an excess entropy for intermediate compositions. The excess entropy at 29...

Introduction: Although feldspar is the most commonly-occurring mineral in the Earth=s crust, its use as a petrogenetic indicator has not been greatly exploited until recently, as evolving analytical techniques have refined characterizations of the amount, valence state, and site occupancy of Fe in the feldspar structure. Understanding of Fe valence and site occupancy in feldspar is of particula...

Alkali feldspars are routinely used in retrospective dosimetry using luminescence methods. However there is a signal loss over time, termed ‘anomalous fading’, which results age underestimation if uncorrected. Although significant improvements have been made recent years, dating of remains challenging. This paper investigates the relationships between chemistry, structural state and scale exsol...