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The present work is conducted in the industrial district south of greater Cairo (ElTabbin area). Some heavy metals like Mn, Co, Ni, Cu, Zn, Pb, Cr, Ba, Cd, Mo were determined in polluted soils during May, 2018. At the study area, results displayed that average heavy metals concentrations differ considerably. They are decreased from Mn to Cd (Mn > Ba > Zn > Cr > Ni > Co > Pb > Cu > Mo > Cd). The average ranges as follows: Mn (255.8–31448.2 ppm); Ba (145.2–17545.6 ppm); Zn (53.3–1589.9 ppm); Cr (26.7–311.3 ppm); Ni (29.7–114.1 ppm); Co (13.2–39.8 ppm); Pb (5.7–77.4 ppm); Cu (7.6–35.2 ppm); Mo (0.1–15.9 ppm) and Cd (0–1.5 ppm), respectively. ElTabbin area has heavy manufacturing activity at Egypt. ElTabbin area was chosen as a model for that contamination. Electrical characteristics of some specimens from El- Tebbin area, Egypt, were taken and measured electrically at frequency range (10−3 to 100 kHz). Major and heavy elements were measured at specimens. Specimens were classified to three categories according to electrical properties. The changes were the consequence of change in minor and major mineral composition in the specimens. Electrical properties were able to recognize different specimens according to different levels of contaminants in the specimens. Texture, tortuosity and minor elements of heavy elements are the controlling factors that control electrical properties at specimens. High values concentration of Mn, Ni, and Zn heavy elements increases conductivity while the high concentration of Pb and Cu heavy elements decreases the conductivity. The mixing up of these different minor and major minerals and elements at specimen may lead to the change of conductivity values. The main controlling factors of the major elements are the Fe2O3 and SiO2, while the main controlling factors of the minor elements are the Mn and Pb. Our main objective is to study mixing up of the different minor and major minerals and elements on electrical properties of rocks., Physical chemistry, Geochemistry, Geology, Geophysics, Earth sciences, Hydrology, Condensed matter physics, Physics methods electrical conductivity, Dielectric constant, Impedance, Mineralogy.

Dolostones of Um Bogma and Um Gheig Formations were studied using mineralogical and geochemical characterizations. The present work has tried to identify the origin, environment, pollution, and their electrical properties for the two formations. Also, the environmental geochemistry that resulted from the trace element concentration is examined here and we will try to differentiate between them. The study samples are fissile and highly fossiliferous dolomites. The two formations are classified as dolostones and nearly ordered. The mineralogy and geochemistry studies indicated that the two formations were formed under mixing zone at the near-surface oxidizing environment. The diagenetic features of both formations demonstrate many processes with clear effects. Dolostones of both formations may be precipitated from two different solutions. Meteoric water is the main supply, while the other solution may be resulted from the deep hydrothermal solutions that come up from deep faults. The distribution of Sr and Y content of dolostones at Um Bogma Formation indicated that they are precipitated at 110–150 °C, while those in Um Gheig are deposited at

Realization of electrical and petrography of rocks is absolutely necessary for geophysical investigations. The petrographical, petrophysical and electrical properties of sandstone rocks (El-Maghara Formation, North Sinai, Egypt) will be discussed in the present work. The goal of this paper was to highlight interrelations between electrical properties in terms of frequency (conductivity, permittivity and impedance) and petrography, as well as mineral composition. Electrical properties including (conductivity and dielectric constant) were measured at room temperature and humidity of (∼35%). The frequency range used will be from 10 Hz to 100 kHz. Slight changes between samples in electrical properties were found to result from changes in composition and texture. Electrical properties generally change with grain size, shape, sorting, mineralogy and mineral composition. The dielectric constant decreases with frequency and increases with increasing clay content. The conductivity increases with the increase in conductor channels among electrodes. Many parameters can combine together to lead to the same electrical properties. The samples are mainly composed of sand with clay and carbonate.

Electrical properties of some sandstone rocks (conductivity and dielectric constant) were investigated as a function of frequency (100 Hz to 100 kHz). Such heterogeneous specimens contain semiconducting constituents (silt and clay) and insulating constituents (sand, air, and carbonates). A theoretical pseudo-random renormalisation group method was used to predict the electrical properties of such random mixture. Four phases were used in the model to consider the detailed texture of the constituent materials. The measured electrical properties (conductivity and dielectric constant) versus frequency of these samples were analysed to predict the texture or connections of these four phases. From the analysis, these four phases were suggested to be (1) carbonates, (2) sand coated with clay and coated with air, (3) carbonates coated with clay and coated with air, and (4) pure sand. The forward problem predicts the electrical properties versus frequency using the pseudo-random renormalisation group method for certain concentrations of the constituent materials distributed among the random four phases. The forward model is used to fit the measured response to obtain the expected concentrations of rock constituents in the proposed four phases using a parameter search method (inverse problem). The obtained accordance between the experimental and modelled characteristics in much of the frequency band used suggests that the pseudo-random renormalisation group method with the supposed four phases reasonably represents the main mineralogical composition of the rock.

Electrical properties of carbonate rocks from North Sinai, Egypt, were investigated experimentally in the frequency domain (100 Hz to 100 kHz). Changes between electrical properties were attributed to changes in mineral composition and texture of samples. Asymmetric mixture laws cannot describe electrical behavior of heterogeneous rocks in the mentioned frequency range. A theoretical pseudo-random renormalization group (PRNG) method was developed to model electrical behavior of rock mixtures. The main goal of this paper is to make forward and inverse modeling using PRNG method for the electrical properties as a function of frequency for carbonate rocks with texture. In PRNG method four phases were used to take into account the texture in the samples. Four phases are the best that we could use in the model. We are trying to increase the competence of the model in the near future. In these four phases mainly conducting constituents (silt and clay) and mainly insulating constituents (sand, air and carbonate) may coat each other. With appropriately chosen coatings for the four phases, the PRNG method can reasonably model the electrical properties of the samples in the measured frequency range. Thus, an inverse problem is used to find the detailed structure of the four phases, which leads to the measured electrical properties of the samples, taking into account the measured concentrations of the different constituents of the samples. The inverse problem is based on minimizing the misfit between the measured frequency response for the conductivity and the dielectric constant and those obtained theoretically from the PRNG method. It was shown that the texture plays an important role in determining the A.C. electrical properties of heterogeneous samples.

Detailed mineralogical and geochemical studies were carried out on the middle members of the black shales of the Duwi Formation (Quseir–Safaga province) to define their source rock, paleo-weathering, pollution impact and provenance of the sources. The studied black shales are highly fossiliferous and fissile. They are texturally classified as phosphatic marly mudstone microfacies. The black shale mineral composition is mainly composed of calcite, apatite, quartz, pyrite and clay minerals. The average values of Cu, Ni, Zn, Cr, V, As and Se and the ratios Rb/Sr and Cr/Ni in black shale are enriched compared to those of the Post-Archean Australian Shale (PAAS) values. Electrical properties of samples were measured using a non-polarizing electrode, at room temperature (∼18 °C), and relative atmospheric humidity of (∼35%), in the frequency range from 42 Hz to 5 MHz. The changes in electrical properties were argued to be due to the change in mineral composition. Generally, the electrical properties of rocks are changed due to many factors such as grain size, mineral composition, grain shape and inter-granular relations between grains. The dielectric constant decreases with frequency, and increases with conductor concentration. Also, the conductivity increases with the increase of conductor continuous paths between electrodes.

The Jurassic sedimentary section in north Sinai is of a special interest in particular for its economic potentiality. The understanding of petrographical and electrical properties of these rocks is essential for investigating minerals and oil and water exploration. This paper presents a study of the petrographical and A. C. electrical properties of Jurassic carbonates. Electrical measurements have been conducted for twenty-nine (18) carbonate samples. The slight changes between samples in electrical properties were attributed to the changes in mineral composition, texture pore spaces and pore throat distribution of the samples. Electrical properties generally change with many factors (grain size, mineral composition, grain shape and facies). The dielectric constant decreases with frequency and increases with the presence of conductive solids (silt and clay) and its composition. The conductivity increases with the increase of conductor paths between electrodes. The main goal of this paper is to shed more light on interrelations between electrical properties (conductivity, dielectric constant and impedance as a function of frequency), petrography and mineral composition (carbonates that contain clays and quartz grains).

The geochemical, petrographical, and electrical properties of rocks are essential to the investigation of the properties of minerals. In this paper we will try to present a study of the A. C. electrical properties of carbonate rock samples and their relation to petrographical and geochemical properties. Samples were collected from four formations from the Bir Dungul area, in the South Western Desert, Egypt. The electrical properties of the samples were measured using a non-polarizing electrode, at room temperature (~28 °C), and at a relative atmospheric humidity of (~45%), in the frequency range from 42 Hz to 5 MHz. The changes in the electrical properties were argued to the change in mineral composition. Generally, the electrical properties of rocks are changed due to many factors e.g., grain size, mineral composition, grain shape and inter-granular relations between grains. The dielectric constant of samples decreases with frequency, and increases with conductor concentration. Also, the conductivity increases with an increase of continuous conductor paths between electrodes. The petrographical and geochemical studies reveal that the deposition of the tufa deposits occurred in shallow lakes accompanied by a high water table, an alkaline spring recharge and significant vegetation cover. Diagenetically, tufa deposits were subjected to early and late diagenesis. Petrography and geochemistry studies indicated that the area of tufa deposits was deposited under the control of bacterial activity. Geochemically, the Sr content indicates that the tufa deposits formed from dissolved bicarbonate under the control of microbes and bacterial activity.

The effect of increasing SiO 2 at the expense of B 2 O 3 on the internal structure of xSiO 2-(40-x) B 2 O 3-60Bi 2 O 3 glass matrix (where x=0, 10, 20, 30 and 40 mole %) was investigated. The glass structure was indicated that Bi 3+ cations are incorporated in the glass structure as pyramidal [BiO 3] and [BiO 6] octahedral units and boron ions are incorporated in BO 3 and BO 4 units. The presence of distorted [BiO 6] octahedral units in the glass network was observed and the degree of distortion was found to be decreased on progressive substitution of B 2 O 3 by SiO 2. The results revealed that increase of SiO 2/B 2 O 3 replacements, led to increase the density, microhardness and chemical durability of the studied glasses. However, the molar volume was decreased. The increase of SiO 2/B 2 O 3 replacements generally decreased the AC conductivity. That decrease may be due to the decrease in distortion of [BiO 6] octahedral units in glass network on progressive substitution of B 2 O 3 by SiO 2. Dielectric constants of the samples are complex, which may be an indication of the distortion (number of free charges or broken bonds) in the network of the glass. The obtained experimental data were argued to the internal structure of glass network and the change of the structure of the samples from pyramidal to octahedral and the presence of boron ions in BO 3 and BO 4 units.

Electrical methods are used in a wide range of applications including groundwater, geothermal, mineral discovery, oil and gas exploration, and deep tectonic processes. The Jurassic sedimentary section in North Sinai is of a special interest in particular for its economic potentiality and environmental conditions such as continental, marine, fluviomarine. The understanding petrographical and electrical properties of these rocks are essential for investigating minerals, oil, and water exploration. This paper presents a study of the petrographical and AC electrical properties of the Jurassic carbonates. Electrical measurements have been conducted for twenty nine (29) carbonate samples. The slight changes between samples in electrical properties were attributed to the changes in mineral composition, texture pore spaces, and pore throat distribution of the samples. Electrical properties generally change with many factors (grain size, mineral composition, grain shape, and facies). The dielectric constant decreases with frequency and increases with the presence of conductive solids (silt and clay) and its composition. The conductivity increases with the increase of conductor paths between electrodes. The main goal of this paper is to shed more light on interrelations between electrical properties (conductivity, dielectric constant and impedance as a function of frequency), petrography, and mineral composition (carbonates that contain clays and quartz grains). This is the first time to make some complex electrical properties on the carbonate rocks at this area as a prelude to make forward and inverse modeling.

The influence of adding Fe2O3 at the expense of Na2O in sodium lead borate glasses on the structural, physical and electrical properties have been investigated. Results obtained from Fourier transform infrared (FTIR) spectra indicated that Fe2O3 plays an important role in converting three coordinated boron atoms [BO3] to four coordinated boron atoms [BO4]. The physical properties such as density and molar volume helped to evaluate the compact structure of the prepared glass samples due to presence of [BO4] groups. The increase of Fe2O3/Na2O replacements led to increasing the microhardness values and decreasing the thermal expansion coefficients of the studied glasses. The increase of Fe2O3/Na2O replacements generally decreased the AC conductivity. That decrease might be due to converting of the three coordinated boron atoms [BO3] to four coordinated boron atoms [BO4]. Dielectric constants of the samples might be an indication of the distortion in the coordinated boron atoms. The obtained experimental data indicated the internal structure of glass network and the change of the structure of the samples from three [BO3] to four coordinated boron atoms [BO4].

SUMMARY Therehasbeenincreasinginterestintheelectricalpropertiesofrocksatdifferenttemperatures. Studies of the electrical properties under high temperatures became important to understand the materials within the earth’s interior. This paper reports on the development of forward and inverse modelling of the electrical properties of the samples considering their internal texture. Sediments in Hammamat area, Egypt, containing magnetite, were extensively heated by intruded magma. As a result, magnetite was altered to hematite with different degrees according to the distance from the intrusion. Complex impedance measurements in the frequency range from 10Hz to 100kHz were performed on samples taken at different distances from the magmatic intrusion. It is supposed that the conductivity will decrease with increasing distance from the intrusion due to the decrease of the conductive magnetite and increase of the much less conductive hematite, but our results show the opposite trend. Conventional mixture laws cannot interpret this abnormal behaviour. A new pseudo-random renormalization group method was developed to model the samples properties with four supposed constituents to match the experimental results. The four constituents are magnetite blocked by air, hematite blocked by air, sand covered by hematite and magnetite covered by hematite. Thefitting results with the experimental data show that as the samples are more heated, volume of the air pores, blocking the hematite and magnetite, decreases due to partial or complete melting, causing an increase in the sample conductivity in spite of the decrease of the magnetite content. This shows that the pseudo-random renormalization group method can model the abnormal properties of the samples. The texture represented mainly by blocking air has a larger effect on the samples conductivity than the concentration of the conductive magnetite.

Understanding petrographical, geochemical and electrical properties of rocks is essential for investigating minerals. This paper presents a study of the petrographical, geochemical and A.C. electrical properties of carbonate rock samples. The samples collected show six lithostratigraphic rock units. Electrical properties were measured using a non-polarizing electrode at room temperature (∼20°C) and a relative atmospheric humidity of ∼50% by weight in the frequency range from 42 Hz to 5 MHz. The difference in electrical properties between the samples was attributed to the change in composition and texture between the samples. Electrical properties generally change with many factors (grain size, chemical composition, grain shape and facies). The dielectric constant decreases with frequency and increases with conductor composition. The conductivity increases with the increase of conductor paths between electrodes. Many parameters can contribute to the same result of the electrical properties. The main objective of the present study is to shed more light on the relation between the texture and geochemical composition of measured samples (carbonates that contain clays and quartz grains) through electrical laboratory measurements (conductivity and dielectric constant as a function of frequency).

This paper is devoted to study the effect of saturation, with distilled water, on AC electrical conductivity and dielectric constant of a fully and partially saturated hematitic sandstone sample (Aswan area, Egypt). The saturation of the sample was changed from full saturation to partial saturation by air drying. Complex resistivity measurements at room temperature (∼16 ◦ C) were performed in the frequency range from 10 Hz to 100 kHz. We used non-polarizing Cu/CuSO4 gel electrodes. Experimental electrical spectra indicate, generally, that the electrical conductivity and dielectric constant vary strongly with water saturation and frequency. The low-frequency electrical conductivity and dielectric constant are supposed to be mainly controlled by surface conduction and polarization of the electrical double layer. Power law behaviours with frequency were noticed. The change in electrical conductivity and dielectric constant with increasing water content is fast at low saturations and slow at high saturations. The behaviour of the electrical conductivity and dielectric constant, with increasing water content, was argued to be the orientational polarization of bound water for very low saturations, displacement of the excess surface charges for relatively low saturations and free exchange of excess ions in double layer with the bulk electrolyte and generation of transient diffusional potentials, which lag behind the applied field for high saturations in addition to membrane polarization on clay and at inter-grain and grain surface water throats having selective charge transport properties. Also, from the data a semi-percolation behaviour was found that has a peak of dielectric constant at a certain concentration and an abrupt change in conductivity at another saturation.

Electrical properties and X-ray diffraction of 20 hematite sandstone samples of the most economically interesting Egyptian iron ore deposits have been investigated. Samples were collected from two different areas in Egypt (Aswan and Bahariya). Complex impedance measurements in the frequency range from 10 Hz to 100 kHz were performed at room temperature (∼20 °C). The observed dielectric behavior was characterized by Maxwell–Wagner interfacial polarization at low frequencies and bulk polarization at relatively higher frequencies. The frequency dependence on conductivity shows a classical relaxation behavior followed Jonscher’s universal law. The measured electrical properties vary strongly with the frequency and sample composition. The difference in the electrical properties may be attributed to the fluctuations in the concentration of the sample constituents and to the degree of heterogeneity of the grains. The XRD-patterns of Egyptian iron ore deposits prove that the main phases are hematite and quartz.

The thermal effects of magmatic intrusion on the conductivity and dielectric constant of magnetic rocks from Hammamat sediments, NE desert, Cairo, Egypt (latitude ∼27° and longitude ∼33°) were investigated experimentally in the laboratory using non-polarizing electrodes. Granitic magma was intruded into the Hammamat sediments, which are a mixture of mainly magnetite with sandstone and due to the thermal effect the area around was extensively heated and altered to different degrees. Due to this magma intrusion, magnetite was transformed (by heating) to hematite to different degrees according to its location from the intrusion. Complex impedance measurements were performed in the frequency range of 10 Hz to 100 KHz at normal temperature (∼20°C) and at a relative humidity of ∼50% RH. Samples were collected at different locations perpendicular to the core of the magma intrusion. Experimental data indicate that the electrical properties vary strongly as we move away (with distance) from the magma intrusion. The conductivity of hematite is ∼10- 2 S/m and that of magnetite is ∼10 4 S/m. As we move from magnetite to hematite (to the core of the magma intrusion) it is supposed that the conductivity will decrease but it was found that the conductivity increases (which is supposed to be abnormal). The conductivity increases with increasing frequency from ∼10 -8 S/m to ∼10 -5 S/m with almost power-law dependence on frequency. The conductivity increases in the order of one decade due to the variation from magnetite to hematite. The increase of conductivity, as we move from magnetite to hematite, was argued to be due to the heating that partially or completely melts the samples, thus the porosity of the samples was decreased and accordingly the conductivity and dielectric constant increased. It was also supposed that the grains of the conductor in the samples are coated or isolated with insulator material. A percolation behaviour for the conductivity and dielectric constant, characteristic of random conductor-insulator mixtures, was found with distance, where continuous paths of the conductive material occur accompanied by peaking of the dielectric constant. Complex impedance plots show that as we move in the direction of altered samples (towards hematite) the relation between real and imaginary impedance changes from a linear form to an arc of a depressed semicircle and increases in depression as we move in the direction of the altered samples, which is consistent with the above interpretation.

The AC electrical data, measured in the frequency range 0.1 Hz–5 MHz, were used to study the electrical response of lithium barium titanium alumino borosilicate glass-ceramics containing strontium or magnesium. Complex plane plot from these electrical data for various glass ceramic samples reveal contributions from simultaneously operating polarization mechanisms to overall dielectric behaviour. The SrO/BaO or MgO/Al2O3 replacements resulted in the increase of the conductivity and dielectric constant of the corresponding glass-ceramic materials. The relationships between the crystalline phases formed and dielectric values of studied glass-ceramics are complicated. The complex impedance of the crystalline materials generally decreases with the addition of SrO instead of BaO and with increase of MgO at the expense of Al2O3. The obtained data were correlated to the internal microstructure, crystalline phases formed, glassy matrix and glass to crystal interface region. β-Spodumene together with varieties of Ba-containing phases [e. g. orthorhombic celsian—BaAl2Si2O8, fresnoite—Ba2(TiO)Si2O7], barium silicate Ba2Si3O8, lithium borate—Li6B4O9, lithium metasilicate—Li2SiO3 strontium titanate—SrTiO3, and magnesium borate—MgB4O7 phases were mostly developed in the crystallized glasses. The microhardness characteristics of the crystalline glasses have been investigated by Knoop microhardness. The SrO/BaO or MgO/Al2O3 replacements resulted into decreasing the microhardness values. The obtained data of the glass-ceramic specimens were explained in relation to the crystalline phases, microstructure formed and the glassy matrix.

The ac electrical properties of some lithium silicate glasses and glass-ceramics containing varying proportions of Y2O3 and/or Fe2O3 were measured to investigate their electronic hopping mechanism. There is a clear variation of these properties with composition. The obtained results were related to the concentration and role of Y2O3 and/or Fe2O3 in the lithium silicate glass structure. In crystalline solids the electrical properties data obtained were correlated to the type and content of the mineral phases formed as indicated by X-ray diffraction analysis (XRD). The conductivity, dielectric constant and dielectric loss of the studied glasses were studied using the frequency response in the interval 30 Hz–100 KHz and the effect of compositional changes on the measured properties was investigated. The measurements revealed that the electrical responses of the samples were different and complex. The addition of Y2O3 generally, decreased the ac conductivity, dielectric constant and dielectric losses of the lithium silicate glasses. The addition of Fe2O3 in Y2O3-containing glasses increases the conductivity, while, the dielectric constant and dielectric losses were found to be decreased. However, the addition of Fe2O3 instead of Y2O3 led to decrease the ac conductivity and increased their dielectric constant and dielectric losses. The obtained data were argued to the internal structure of the lithium silicate glass and the nature or role-played by weakness or rigidity of the structure of the sample. Lithium disilicate-Li2Si2O5, lithium metasilicate-Li2SiO3, two forms of yttrium silicate Y2Si2O7 & Y2SiO5, iron yttrium oxide-YFeO3, lithium iron silicate-LiFeSi2O6 and α-quartz phases were mostly developed in the crystallized glasses. The conductivity of the crystalline materials was found to be relatively lower than those of the glass. At low frequency, as the Y2O3 content increased the ac conductivity, dielectric constant and dielectric loss data of the glass-ceramics decreased. However, the addition of Fe2O3 to the Y2O3 containing glass-ceramic led to increase the conductivity. The addition of high content of Fe2O3 instead of Y2O3 in the glass ceramic led to increase the ac conductivity.

The effect of replacing BaO by SrO or Al2O3 by MgO on the structure and some physical properties of the glasses of the system Li2O-B2O3-(SrO)BaO-(MgO)Al2O3-SiO2—containing TiO2 have been investigated. Fourier transform infrared (FTIR) spectroscopy revealed that the addition of SrO at the expense of BaO gives no changes in the main structural building units. The addition of MgO instead of Al2O3 decreases the fraction of BO3 and increases the fraction of BO4 groups. Dilatometric measurements showed that the thermal expansion coefficients (α-values) were increased by gradual addition of SrO or MgO instead of BaO or Al2O3, respectively, however the transformation (Tg) and softening (Ts) temperature values of the glasses were decreased. The density was found to decrease as SrO/BaO or MgO/Al2O3 replacements increased. The conductivity, dielectric constant and dielectric loss (dielectric constant × loss tangent) of the glasses were investigated using the frequency response in the interval 200 Hz-100 KHz and the effect of compositional change on the measured properties was investigated. Measurements showed that the electric responses of samples were different and complex. The addition of SrO instead of BaO generally, increases the conductivity, dielectric constant and dielectric losss of the glasses. Increasing the MgO at the expense of Al2O3, the conductivity and dielectric constant of the glasses were decreased. However, the dielectric losss was increased. The electrical properties were found to be factors that are able to distinguish the various electrical parameters as a result of the change in composition. The obtained data were correlated to the internal structure of the glasses and the nature and role played by glass forming cations.

This paper focuses on the effect of water saturation on A. C. electrical conductivity and dielectric constant of fully and partially saturated hematitic sandstone sample (Aswan area, Egypt). The saturation of the sample was changed from partial to full saturation. Complex resistivity measurements at room temperature (~16°C), were performed in the frequency range from 0.1 Hz to 100 KHz. Experimental electrical spectra indicate, generally, that the electrical conductivity and dielectric constant vary strongly with water saturations and frequency. The low frequency electrical conductivity and dielectric constant are mainly controlled by surface conduction and polarization of the electrical double layer. The behaviour of the electrical conductivity and dielectric constant, with increasing water content, were argued to the orientational polarization of bound water for very low saturations, displacement of the excess surface charges for relatively low saturations, and free exchange of excess ions in double layer with the bulk electrolyte and generation of transient diffusion potentials which lag behind the applied field for high saturations.

Sand is a heterogeneous mixture of crystalline silica and air. Natural humid sand samples show abnormal electrical behaviour. Mixture laws such as MaxwellWagner and Bruggeman laws cannot describe this abnormal electrical behaviour. Percolation theories can predict this behaviour around the critical concentration only. The purpose of our study is to extend the applicability of a pseudorandom network model, used successfully by (Gomaa et. al., 1999 a, b) to fit experimental data of natural hematitic sandstone, and following renormalization group method, to fit the experimental data of (Shahidi et. al., 1975), for sand samples with different humidities, in the frequency range