ABSTRACT: Rubble mound breakwater is one of the most important structures for shore and harbor. Durable and high quality natural rocks are commonly used to protect coastal engineering structures from the waves. In this study, numerous laboratory tests were performed for the quality assessment of different basalt levels for rubble mound breakwater in the Yumurtalik (Eastern Mediterranean) region in this study. Two different basalt types were observed in study area. These levels were evaluated with different rock quality classification systems. Basalts were grouped in to two classes as massive and vesicular. Iddingsite is a product of alteration of olivine minerals, which are commonly observed in the vesicular basalt. Vesicular basalt levels showed poor rock material strength due to alteration. The vesicular basalt levels in the study area should not be used for armourstones.