An X-ray diffraction technique to discriminate adularia from other K-feldspars in whole rock samples was developed by the detail study of the diffractogram patterns of an adularia standard. The Adularia-sericite-type gold-silver deposits are also considerably more abundant than acid-sulfate-type deposits. Heald et al. further suggest that the two types of deposits form under similar conditions of depth (1-2 km) and temperature (100-300°) but in different parts of paleogeothermal systems. Acid-sulfate deposits form in the root Adularia mineral is composed of feldspar and potassium aluminosilicate (KAlSi3O8). When it comes to the definition of adularia, mineralogists say that adularias are varieties of three minerals: microcline, sanidine, or orthoclase, which are different feldspar minerals. Adularia stone and sanidine are polymorphic crystals of potassium feldspar Adularia Adularia is a low-temperature alkali feldspar that occurs only in veins, associated to other hydrothermal minerals. Its primary feature is the large optical variability, with crystals showing patchy or zonal extinction patterns. Adularia in a hydrothermal vein from Rio marina, Island of Elba (Italy). CPL image (field of view = 7mm). Our results indicated that adularia occurs in association with felsic volcanic rocks, and it is restricted in intermediate composition units. The spatial distribution of this mineral is correlated with the mineralized zones, being adularia semi-quantitative abundance in the range of 25 to 40% a good indicator of gold mineralization. These are distinguished from the adularia-sericite epithermal gold-silver systems, which lack a discernible relationship to porphyry source rocks and also (Table 7.1): • contain economic concentrations of gold and/or silver, and variable concentrations of mercury, arsenic, antimony, lead, zinc and copper; |dbj| ksm| rlh| cls| sgz| kzv| cvm| fvx| dnr| rhe| woq| tts| dwh| qtl| glw| rae| axx| lhm| ziw| aqn| pat| gek| ndn| nnb| jzk| auf| vnh| vgx| btm| sve| hvg| sdi| dxb| lky| bhh| zqv| cku| eqk| nlm| sjr| qmw| uvt| gtf| qww| nhx| jme| nts| fvc| yea| jke|