Minerals, Rocks and Soil

Minerals Minerals are a natural, nonliving, solid substance that has a definite chemical structure. Simply put “Minerals make up rocks.”

Properties of Minerals Luster- how light reflects(shiny or dull). Color/ Streak-colored powder left on a ceramic streak plate. Texture- rough or smooth. Hardness- (1-10) on the Moh’s Scale. Malleable- how easily softened. Fracture/ cleavage- how it breaks. Density

Three Kinds of Rocks The three kinds of rocks are Sedimentary, Metamorphic, and Igneous Rock.

Sedimentary Rock Sedimentary Rock is formed from pieces of rock and minerals that are formed in layers. Sedimentary rock is a “History Book”, because more fossils are found there than anywhere else.

Fossils Fossils can form when an organism is buried in soft mud. Most fossils form from hard parts, such as bones, shells, or wood, that does not decay. Most are found in layers of sedimentary rock.

Types of Fossils The three types of fossils are: mold, cast, and imprint..

Metamorphic Rock Metamorphic Rock is formed when heat, pressure, and chemical reactions change one rock type to another kind of rock.

Igneous Rock Igneous Rock is formed when magma (the molten rock inside the Earth) cools and hardens. Volcano craters and areas around hot springs are covered in Igneous Rock.

What is Soil? Soil is weathered rock, air, water, and the remains of living organisms. Soil is found in three layers: topsoil, subsoil, and bedrock/ parent rock. The topsoil is darker in color, because it contains a lot of humus. Humus is made of decayed plant and animal matter.

The Three Kinds of Soil There are three main types of soil: clay, silt, and sandy soil. Clay soil hold water very well. Silt have a medium texture and does not hold water as well as clay. Last, sandy soil is large grained and doesn’t hold water very well. A combination of sandy soil and silt is called loam.

Soil Layers The soil usually appears in layers. The topsoil is first, then subsoil, and last the parent rock.