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Kaolin is found in deposits of economic concentration in the Jabal Al-Harad/ Batn El-Ghoul area in southern Jordan. Ten representative kaolin samples were collected from the area and investigated for their mineralogical and chemical composition. Mineral characterization was carried using X-ray powder diffraction (XRD), thermogravimetrical analysis (TGA), differential thermal analysis (DTA), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). X-ray fluorescence (XRF) studies were conducted to determine the chemical composition of the kaolin deposits. Kaolinite was the predominant mineral, followed by quartz, with traces of illite-muscovite, Fe-bearing minerals (hematite), anatase and feldspar. The average chemical composition of the kaolin samples was 58.02 wt.% SiO2, 28.00% Al2O3, 1.48% Fe2O3, 1.26% TiO2and 0.41% K2O (ignited basis). Dehydroxylation and mullitization temperatures (from DTA) were close to the theoretical values. Hexagonal booklets and stacks of kaolinite, as well as individual platelets, were present in the Jabal Al-Harad kaolin. Based on granulometric and descriptive mineralogical analyses, the mineral assemblages and kaolinite morphology, the Jabal Al-Harad kaolin deposit is thought to have originated from greatly weathered surfaces related to the Precambrian basement rocks. The kaolin was found to be suitable for manufacturing of common bricks, medium-fired bricks and sanitary ware, although a beneficiation process would be required; it could also be used in the refractory, white cement, paper and advanced ceramic industries.

The growth and dissolution kinetics of potassium sulfate was studied based on single crystal measurements. The growth rate is correlated to the supersaturation with power low equation. At all the temperatures studied, the growth rate order lies in the range of 1-1.5 with the surface integration process as the controlling step. The estimated value of the activation energy of growth is 39.4 kJ/mol. The dissolution rate order decreases with increasing the temperature. The diffusion step is controlling the dissolution process. The addition of 5 ppm Cr 3+ ions reduces the growth rate. Both growth rate dispersion and dissolution rate dispersion occur in the growth and dissolution processes of potassium sulfate.

The source of the feldspar is found in the Late-Precambrian granitoid rocks of Al Madinah area, which covers about 2000 km 2 within a 44,000 km 2 area of the western part of Saudi Arabia. Petrographical and geochemical study shows that the granitic rocks have a considerable compositional range from quartz monzonite, quartz syenite, syenite, alkali granite to alkali feldspar granite. Mineralogical and petrographical results have revealed that Al Madinah granites are composed of quartz, K-feldspar, Na-plagioclase and muscovite. Geochemical data for the feldspar samples show average SiO