Petrography lower if wholly or partly vitreous. The specific gravity of the more common rocks range from about 2.5 to 3.2. Archaeologists use petrography to identify mineral components in pottery. This information ties the artifacts to geological areas where the raw materials for the pottery were obtained. In addition to clay, potters often used rock fragments, usually called "temper" or "aplastics", to modify the clay's properties. The geological information obtained from the pottery components provides insight into how potters selected and used local and non-local resources. Archaeologists are able to determine whether pottery found in a particular location was locally produced
Empirical study of literature raised to the empirical study of literature are the triviality of many of its research results such as confirmation of what was already known or suspected or its reductionism (artificiality of the framework and set-up, and limitation to reader response instead of the study of the text). It is clear, however, that the empirical study of literature by its specific approach of the object and its focus on methodology is an outstanding way to explore the socio-cultural aspects of the literary system. It makes an irreplaceable contribution to the development of a more rational, scientific, and socially relevant study of