مجله بلور شناسی و کانی شناسی ایران
سال پنجم شماره 1 (پیاپی 10، بهار 1376)

Do lomites and limestones o f simmilar age as Soltanieh and paleozoic forma tio ns have been tr ansformed to coa rse grained granoblas tic marbles due to in tru sion of granitic masses, located 4 km southeast of Lahijan, Iran, and barite mine ralization have also occurred. Ore mine ra ls are mos tly co ncentr a ted along th e rracture zones in do lo mites and mining activeities in the past was foc used on these fractures and breccia zones. Studies of polished sections under the ore microscope have shown that the major o re mine rals occurring in veins contain magne tit e, pyr ite,pyrot ite chalcopyrite, hematite, goetite, and Cchr('39')I ~ M g- Fc s ili ca t e~ such as phlogo pite, talk, act inolite, thremolite, diopsidc and chlorite. Magnetite is the major iron mine ral in skarn. This mineral and pyro tit c are considered to be primary and the remaining minerals are considered as second ary. Barite veins with eas t~wes t trends formed by hydrothe rmal activi ties are o bserved in dolomiti and schists ri ght next to the intru sio ns, a round villages such as Di zin and Sarches hmeh. Conside ring the min eralogy, texture and stru cture or these ve in s, it is probab le that they a re crys tallized in fractures at temperatures below 500

Single crystals of CdTe were grown by the sublimation and condensation technique in a silica, under an argon gas now, and also by alloing cadmium tcJloride transport within an evacuated silica ampoule. X-ray powder diffraction patlerns prepared from each group of grown crys tals showed the crystal structure of the examined samples to be zinc-blend race-cent red cubic. Transmission electron microscopy of CdTe single crysta ls confirm the cryst:il structu re to be face-centred cubic with a = 6.5(3) A. and space group F 43m.

Thin films of superconductor YBaCuO(YBCO) and Pb(ZrTi)O(PZT) is grown by laser ablation technique to make an electronic device. The quality and the structure of the films is studied by X-ray diffraction (XRD) and Auger Electron Spectroscopy (AES). A quantitative analysis of the films is also deduced from AES study. Analysis of the films show that the YBCO is grown in (001) and PZT in (100) direction. From this study we also conclude that laser ablation technique is a proper method for thin film production.

Dealumination is a common phenomena occures during acid leaching or acid rctluxing of mordenite to prepare acidic zeolite. But there is no comprehensive repo rt on dealumination which can take place in mordenitcs that are made acidic by ion.exchnge with ammonium sa lt so lution followed by ca lcination. OUf UV Diffuse Reflectance Spectrosco~y on acidic mordenite prepared by ion ~exchangc with NH4 + and followed by ca l cin~tion at 5500C shows dislodging some of the framework aluminium from their tetrahedral si tes . Inspection of UV absorption spectrum of the as.synthesized mordenitc reveals existence of one type of structural A1 only. Whereas, in acidic form of mordeniLc two types of aluminium were observed. Two bands of 220 and 280nm in the acidic mordenite were assigned to lattice and extra· lattice aluminium respectively. Appearing 280nm band in the acidic mordenite prepared by treatment with nitric acid shows extra· lattice aluminium in both types of acidic mordenites may arise from the same AI species and the same environment.

Geological and geochcmical studies in Sinar area, located in the north east of Khonlsan pruvince, indicate the presence of antimony in a vast area. This cleme nt mainly occurs as st ihni te , associated wi th na tive antimony, kerlncsite, getchellite (chr('39')!), pyrite, chalw pyrite. arseno pyrite, tctrahcdrite .md ga lena, in carbonate rock.chr('39')i, as veins. veinlcts and disseminations. The gangue minerals arc calcilc,doiomitc, barite and qua rtt. Inves tiga tions ind ica te that thrust fllulis and brecciated zones arc the most important channclways for migration or arc tluids, and deposi tion of the a re assemblage and The mineralization has occurred in seve ral physico. chcmic<l1 e pisodes. The strategic importance of antimony, and its association with valu<lble commodities such as gold, si lver, mercury and arsen ic, demand more detail inves tigat io ns in this region.

This paper describes the synthesis of barium copper silicate using agglomeration of BaD, CuD, SiOz and borax. The synthesized pigments were then investigated by using X-ray diffraction (XRD) and scanning cleeton microscopy (SEM) techniques. The alkaline oxides, earth alkaline oxides, etc. can reduce the intensity of XRD lines of the samples. In order to confirm the existence of barium copper silicate pigments, the blue and purple glazes were sythesized and their X-ray diffraction lines were then investigated and compared to those for the ancient glazes.