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
The Study of Touch jazz piano trio in the 21st century". Writing for The Guardian reviewer John Fordham called it "A session by a master improvising composer, and in ideal company". On All About Jazz, Mike Jurkovic noted "With boundless humor and flexible grace, pianist Django Bates offers us "The Study of Touch" the perfect piano trio music for the significant other who absolutely hates piano trio music" while Karl Ackermann said "it seems that in teaming with Eldh and Bruun, more than ten years back, Bates was simultaneously laying the groundwork for what has become his own version of a standards trio. In