The minerologic-petrographic properties and gemologic areas of usage of fire opal formation in Simav (Kütahya) region

In this thesis, intented to examine the formation fire opals of Simav (Kütahya), research topics are history of the region, mineralogic petrographic properties and gemologic areas of usage of fire opals, also known as Simav stones. In the content of this thesis these researches are put together to shed a light on geological formations of fire opals. In Dokuz Eylül University, Department of Geological Engineering, Laboratory of Thin Section-Gemology, the samples gathered from the region was used to obtain thin sections and then these this sections are examined in polarizing microscope to acquire a mineralogic-petrographic point of view. In the XRD (X-Ray) studies made on fire opals, opal-C (cristobalite), opal-CT (cristobalite-tridymite) and low temperature quartz crystal were found. As a result of SEM-EDX analyses, amorph formed opal formations and microchrystalline quartz (cristobalite-moganite) and lussanite in chalcedonic crystal phase are observed in fire opals. Besides, there observed many barite formations which further support hydrothermal effect in SEM-EDX studies. There has been made a study about jewellery design works suitable for samples gathered from Yeni Karamanca and prepared cabachons were mountered with silver and a variety of gems was produced.