TRANSVERSE CONTRACTION JOINTS. The primary purpose of transverse contraction joints is to control the cracking that results from the tensile and bending stresses in concrete slabs caused by the cement hydration process, traffic loadings, and the environment.
Diamonds are found in igneous rock which is brought to the surface of the earth by volcanic eruptions bringing magma to the surface. Diamond itself is strictly an allotrope of the element carbon, a mineral, one form of crystal that can be created from carbon.
Introduction to Igneous Rocks. An igneous rock is any crystalline or glassy rock that forms from cooling of a magma. A magma consists mostly of liquid rock matter, but may contain crystals of various minerals, and may contain a gas phase that may be dissolved in the liquid or may be present as a separate gas phase.