One of the main sources of error in sample preparation is contamination resulted by laboratory equipments. Among these equipments, pulverizers and mills have a major impact. In this research, several samples of rock and ore with different abrasive property were pulverized by a tungsten carbide ring mill and analyzed by XRF method. It has shown that some samples were highly contaminated by tungsten and cobalt. The rate of contamination can be directly related to sample abrasiveness and time of pulverizing. Many interference of X-ray fluorescence spectra of tungsten and cobalt with some other elements were also found. In order to get a precise results, it is necessary to reduce or eliminate the interference of these elements by appropriate methods.

The X-ray fluorescence spectrometry and the MA. BM. 006 reference spectrophotometric methods were used to determine the content of SiO2 (%) in bauxites from different deposits. The treatment of samples prior to the analysis involved the following steps: annealing, melting using the borax method, and the formation of beads. Certified reference bauxite samples were used for the calibration curve. The calibration curve was produced with the correlation coefficient of r =0. 9999 and the standard error of S = 0. 0246. The average residual value between the content of SiO2 determined using the XRF method, and the reference method was 0. 045, with a standard deviation of 0. 068. The XRF method was statistically verified by the F-and t-tests (using the standard sample and the reference method). The values obtained in the tests show that the XRF method yields accurate results and that there are no standard errors.

Study of cultural and historical materials excavated from the archaeological excavation is one of the most important goals of Archaeometry, in order to answer a lot of questions in archeology. In this regard, elemental analysis is important factors in the realization of this aim. Numerous analytical methods have been used for this purpose traditionally. Among them, X-ray fluorescence spectroscopy (XRF) methods, inductively coupled plasma spectroscopy (ICP-MS) or neutron activation analysis (INAA) can be noted. In recent years, the use of portable X-ray fluorescence instrument is one of the ways that has been received a lot of attention and is expanding and improving continuously. The good accuracy as well as fieldwork possibility of this non-destructive method has led it to increasingly attains more popularity. In particular, this method has been used more and more in classification and provenance study of pottery and stone artifacts. Although very few institutions in Iran, including Tehran Art University, have access to this tool but due to the unique features of this device, it seems that its use will be expanded in next years. This paper attempts to give a general idea about this technique to the researchers and students, and review its advantages, limitations and application in cultural heritage purposes. There is almost no any other portable analytical tool, which is become so familiar and user-friendly like portable XRF. As this technique is actually a surface analysis and penetration x-ray is limited to some millimeter, the target surface must be free of likely contaminations. However it would help researchers in different fields studies like museum studies, Archaeometry, archaeology, geoarchaeology or conservation of artifact. In theory, all elements except H & He could be identified with this technique. However, identification of light elements with low atomic numbers is very hard. With using a new generation of silicon drift detectors, it is possible that elements from Mg (Z=12) to U (Z=92) be detected. Besides qualitative studies, this instrument has been used widely for quantitative analysis. Classification and provenance studies are the main application of this tool in archaeology. With appropriate calibration and statistical methods reliable results would be acquired. Some examples of ancient potteries from Zanjan are given in this issue.Clustering test (CA) and principle component analysis (PCA) are the two most used statistical methods in interpretation of quantitative results of XRF.

Using the stones to make tools and vessels dated back to Paleolithic and Neolithic periods. Stones so called soft stones, along with the alabaster, are one of the most famous stones that have been used to produce vessel in Near East, where they are in use currently in different applications. Soft stone vessels reach to highest level of flourishing during the Bronze Age and its geographical exchange area stretches from India in east to Syria in west. Iran, as one of the most important places of this kind of stones, was a potentially center in this trade and archaeological sites such as Tape Yahya and Konar Sandal in Kerman province are some of the most famous sites in making and exporting this kind of objects. Although soft stone vessel making continued during historical to Islamic era, but this industry has been neglected by researchers and archaeologist. In addition, until now morphological and artistic reports and archaeometry studies have focused only on Bronze Age vessels. During six seasons archaeological excavations at an Islamic Archaeological site called Shadyakh near to modern city of Neyshabur (about 2 km south east of Neyshabur), which its date goes back to Early and middle Islamic period, many cultural objects, like the pottery, glass, metal, bones, human skeletal, plaster, and architectural remains have been discovered. Beside of these samples, several pieces of soft stone vessels were discovered from several archaeological excavations. No evidence of workshop or crafting was reported and according to geological reports around this region, no outcrop of soft stone was seen. Although that these vessels are important, no study have yet been conducted on them. At this research, the vessels have been archaeometrically studied. The main objective of this research was to gain the information about the structural characteristics of soft stone vessels recovered from this site. Before this, Kohl and his collogues in 1979 carried an investigation on large amount of Bronze Age archaeological samples from Middle East. They found several main groups and a mine around Mashhad was recognized. Other researches on soft stones include Razani’ s M. A and Imami and his colleague’ s researches on new chlorite mines of Ashin; and Afshari Nezhad and Razani’ s research on structural characterization and conservation of Jiroft cultural basin’ s chlorite vessels. The only research on historical and Islamic soft stone vessels was about the effect of cooking conditions on structure of vessels. At this research, totally 16 samples from different seasons of archaeological excavations of Shadyakh were collected and analyzed by XRD, 4 sample analyzed by XRF, and 2 samples by SEM. The results of XRD analysis showed two main groups, while 21 trace elements and 11 chemical compound were detected by XRF. The raw data was studied by Excel statistic software. At this study, overlap graph was prepared according to finding difference or similarity between samples where the results show high similarity among the samples. The SEM and XRD results show that main compounds are Talc, Steatite, Soapstone, Clinochlore, Graftonite, Dolomite, Britholite and Clinochlore. All samples have these compounds, therefore, it could be concluded that Shadyakh samples come from one geological zone.

Considering the growing need for rapid and accurate analysis of zeolites, X-Ray Fluorescence (XRF) spectrometry is a suitable technique for fast analysis without the need for extensive sample preparation. Due to the interaction between the emission of secondary fluorescent radiation and the sample matrix, there is no simple proportion between the intensity of X-ray fluorescence and the content of elements, mainly when the matrix contains heavy elements. The matrix effects cannot be reduced or omitted during sample treatment except for the fusion method which is destructive and time-consuming. Consequently, perfect matching between standards and samples, and adjusting the calibration based on Certified Reference Materials (CRMs) with a matrix quite similar to the test sample are required. Since zeolites are very diverse and CRMs for these materials are not readily available, the semi-quantitative method with low precision and accuracy is inevitably used. The present study describes an innovative XRF calibration method using validated samples and an inert binder, to make some matrix-matched standard samples according to the principles of Green Sample Preparation (GSP). Due to the use of solid-solid sample preparation, the Weighted Least-square linear Regression (WLR) model was applied for the authentic quantitative multi-elemental analysis. Moreover, the effect of the particle size, spectral line interferences, and moisture content of the samples on the accuracy of XRF was assessed. This method was adapted to determine five major elements, including Al, K, Na, Si, and La, in the most common type of zeolites like A, Y, and X. Variations represented that the limits of quantification were 0.20%, 0.18%, 0.31%, 0.16%, and 0.010%, respectively.

The quantitative evaluation of uranium content in the Khoshomi boreholes has been mainly carried out based on logging and XRF laboratory data. In order to determine the correlation between aforesaid data, composition and chemical analysis has been accomplished at 115 zones by considering 3.05 meter intervals that is equal to the length of each drilling rod. In this relation, 55 parts with the core recovery coefficient more than 90% were selected and the correlation between their uranium and thorium contents were studied to determine the amount of radiation resulted from thorium. In the next stage, the regression equation was obtained using two methods, i.e. correlation between the total count and the uranium content, and the thorium depleted radiatiol1and the uranium content. Using the first method, the average estimation error is approximately zero. But, as the estimated error variance is relatively high, complementary information is required for a favorable mining design.