Minerology and petrography of important hard stones produced in Turkey

25 different hard rock samples have been examined and named scientifically within the master thesis subject named Mineralogy and Petrography of Important Hard Rocks Produced in Turkey.The hard rock samples in consideration are the rocks introduced to the sector by the companies that attended to the international marble fairs in Izmir and Istanbul. The criteria used in specifying the samples are: the rocks must be still processed and sold. When possible, the samples have been provided from quarries and sometimes from the firms and companies operating rock.Consequently, thin sections have been prepared and rocks have been grinded to the proper size. Radionuclide Activity experiments have been carried out, experimental results of some rocks have been obtained from previous examinations and these results have been included in the thesis. After chemical analysis and mineralogical examination, rocks have been renamed scientifically. Rocks? mineral compounds and percentages have been determined together with mineralogical examinations. Obtained results have been evaluated in related diagrams and scientific names for the rocks have been defined.The names of the rocks which have been commercially put forward to sales are mostly not matching with their scientific names. In sector, after the analysis, it has been observed that rocks named granite defined as granodiorite, quartz ? monzonite as quartz ? syenite even as quartz ? diorite porphyry etc. Andesite and basalts have come out to be matching with their scientific names generally. As a result of this examination, the rocks which are being sold commercially as diabase has been defined as microgabbro.Keywords: Hard rock, granite, andesite, basalt, diabase, mineralogy