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
What Is This? project while the former was seen as side endeavor. What Is This released their debut EP "Squeezed" in 1984. Around this time, Hillel Slovak had become uncertain of his role in the band and decided to rejoin the Red Hot Chili Peppers. He left What Is This in 1985, and later that year the band would release its only full-length studio album "What Is This?" and its final EP "3 Out of 5 Live". After this, the band broke up. Alain Johannes later met Natasha Shneider and the duo formed Walk The Moon, whose sole studio album featured Jack Irons