Investigation of Geological and Gemological Characteristics of Opal-Chalcedony Formations Observed in Listvenites in the Hatip-Çayırbağı (meram-Konya) Region

Abstract

The geological and gemological features of the chalcedony formations in the Listwaenite found in the ophiolitic rocks in the Hatip-Çayırbağı (Meram-Konya) region are emphasized. The basis of the study area is the Late Triassic-Late Cretaceous Lorasdagı formation and the Late Cretaceous Midostepe formation. These units cover the Late Cretaceous Hatip ophiolite complex with a tectonic contact. All these units are overlain by the Late Cretaceous Çayırbağı Ophiolite with a tectonic contact. It is associated with the Çayırbağı ophiolite, which is unconformably overlain by the Upper Miocene-Lower Pliocene Ulumuhsine formation. It is thought that the chalcedony formations in the region are composed of siliceous solutions associated with Listwaenite and entering into fractures and cracks due to tectonism. As a result of the geological, gemological, Raman, and FTIR studies, it was determined that the formations in the listvenite were chalcedony. Chalcedony formations are generally found between 1-15 cm. Yellow, white and brown banded colorations were observed in the chalcedony formations formed in the spaces in the Listwaenite. The samples were processed as cabochons and facets in the gemstone processing laboratory. As a result of shaping, it was determined that the samples were of cuttable, workable, and polishable quality. In line with the data obtained, it was concluded that it would be appropriate to study other listvenite occurrences in the region and Turkey regarding gemstones.