Günümüzde yapılmakta olan mühendislik projeleriyle birlikte doğal kaynak ihtiyacı da giderek artmaktadır.

The neccesity of natural resource gradually increases with engineering projects which are currently beingcarried out at the present time. For meeting the requirements, basaltic rocks are preferred due to their high strengthand durability. In this context, it is important to know the mineralogical and petrographic characteristics of basalts,which used in engineering applications and when required different sectors, that affect their crack initiating, failurethreshold and as well as the behavior under load. This study aimed to reveal the mechanical behavior of basaltic rockswhich have different mineralogical and petrographic features. Research was carried out on samples that have beencollected from the basalt quarries within Marmara Region and its surroundings. After mineralogical and chemicalcomposition analysis, petrographic properties of basalts were digitized with the help of the image processing. Atthe end of the laboratory studies, mechanic properties were obtained and load values of crack initiation and failurethreshold were determined with acoustic emission method. Obtained result show that load values of crack initiationvalue were found between 0.33σc and 0.54σc and the failure threshold value between 0.83σc and 0.98σc.