CH 2 INSIDE OUR EARTH

A rock is the hard, solid part of the Earth that is not soil or metal. Rocks can be different colors. Some rocks are smooth. Other rocks are very rough.

The cycle has no beginning and no end. Rocks deep within the Earth are right now becoming other types of rocks. Rocks at the surface are lying in place before they are next exposed to a process that will change them. Several processes can turn one type of rock into another type of rock.

Weathering describes the breaking down or dissolving of rocks and minerals on the surface of the Earth. Water, ice, acids, salts, plants, animals, and changes in temperature are all agents of weathering. Once a rock has been broken down, a process called erosion transports the bits of rock and mineral away.

Rock cycle:The cycle in which rocks transform between Igneous, Sedimentary, and Metamorphic via the processes of the earth. Sedimentary Rock: Sedimentary rocks are formed from pre-existing rocks or pieces of once-living organisms. They form from deposits that accumulate on the Earth’s surface.

A crystal is just a mineral that is not part of an aggregated solid, like a rock, but instead stands on its own. Structured lattice-like lattices are used to make crystals. The outcome is an inorganic, geometric structure.

Most minerals can be characterized and classified by their unique physical properties: hardness, luster, color, streak, specific gravity, cleavage, fracture, and tenacity.

A crystal is just a mineral that is not part of an aggregated solid, like a rock, but instead stands on its own. Structured lattice-like lattices are used to make crystals. The outcome is an inorganic, geometric structure.

“An oxidation reaction you might be familiar with is rusting — when metal reacts with the oxygen in the air and becomes rust,” Kapp said. “In rocks, it is little grains of minerals like hematite and magnetite that have iron in them. Those minerals experience oxidation and become rust, turning the rocks red.”

Other Red or Pink Minerals Other truly red minerals (crocoite, greenockite, microlite, realgar/orpiment, vanadinite, zincite) are rare in nature, but common in well-stocked rock shops.

Rocks may be various colors, depending on what they are composed of and whether they were formed under oxidizing conditions. Iron minerals in rocks deposited in deep water, such as in the ocean or deep lakes, are less oxidized, and these rocks tend to be black or gray.