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.
Igneous Rocks. Igneous rocks form directly from magma inside the earth's crust (called: plutonic or intrusive) or lava on the earth's surface (volcanic or extrusive).Light-colored igneous rocks (pumice, rhyolite & granite) are composed of larger amounts of silica and are said to be felsic (feldspar + silica).gneous Rocks. Igneous rocks form directly from magma inside the earth's crust (called: plutonic or intrusive) or lava on the earth's surface (volcanic or extrusive).