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
Here Is What Is Here Is What Is Here Is What Is is the fifth studio album by Canadian songwriter and record producer Daniel Lanois. It was first released in December 2007 as a high-quality download, and later released on CD on March 18, 2008. The album is the result of the same project that led to the 2007 documentary "Here Is What Is" that premiered at the 2007 Toronto International Film Festival in September. The movie documents the aesthetics and creative process behind Lanois' approach to music making and recording. The album has been presented as a direct soundtrack to this film, and