Rocks and minerals

Metamorphic rocks are made by heating or extruding the crust. They often appear in the mountains. An example is slate. Slate was originally black dirt on the bottom of the sea or the bottom of the lake. Fossils can sometimes be found among them, but they are often crushed. Other common metamorphic rocks are called marble, gneiss, schist

Metamorphic rocks are the result of existing rock deformation. The original rock is exposed to very high heat and pressure. Examples of these rock types are marble, slate, gneiss and schist.

They may be formed by deep underground pressure, continental collision, other structural processes, or hot lava infiltration called magma inside the Earth.

Dark colors (usually black, brown or green) containing iron and magnesium (olivine, pyroxene, amphibole and biotite) among common rock forming minerals are called mafic minerals. White, pink or colorless light-colored rock forming minerals (feldspar and quartz) are known as silicic materials. It should be noted that the color of minerals should be observed on newly exposed surfaces, as the surface of minerals often discolor under the influence of weather. Individual colors are not reliable attributes to identify minerals. Some minerals have the same color, and some minerals may be displayed in different colors.

The Earth is covered with a layer of hard rock called the crust. Rocks are sedimentary, volcanic or metamorphic. Almost all rocks are made of minerals, but different rocks contain different mineral mixtures. For example, granite consists of quartz, feldspar and mica. Rocks can be distinguished by their overall color, the minerals they contain, the size of mineral particles, and their texture (mixture of particle sizes). The hard rocks that make up the Earth's crust are called bedrock. It can be seen on coast and mountains, where it is eroded and worn. Erosion breaks the rock into small pieces and forms soil and sediments covering the bedrock in most places (mud, sand, gravel, etc.). Deposits may later become sedimentary rocks

Sedimentary rocks - sedimentary rocks have been formed and cured by sediment compression for many years. Generally, things like streams and rivers carry large amounts of small rocks and minerals to larger water bodies. These debris will sink to the bottom and for a long time (perhaps millions of years) they will form a strong rock. Examples of sedimentary rocks are shale, limestone, sandstone and the like.