Comparisons of rocks and minerals and how they are related
A mineral is a substance found in nature. They are solid, non-living substances. Minerals are made of atoms Earth has more than 3,500 different kinds of minerals.
Crystal shape – A mineral’s atoms can make shapes called crystals. The crystal gets its shape from the way the atoms inside are arranged. Crystals have smooth, flat surfaces and sharp edges. Cubicorthorhombic rhomboid
Hardness Hardness test – Mohs scale from 1 – 10 Talc # Diamond #10 Streak – The colored line a mineral makes on a plate.
Some minerals break apart in a special way. CleavageFracture Color Luster
When minerals mix together, they become rocks. Magma is made from many minerals. As magma cools, the minerals harden together and become rocks.
Igneous rocks are rock made from cooled magma. ObsidianGraniteBasalt
Metamorphic rocks are changed by being heated and squeezed. Metamorphic rocks are usually very dense. Gneiss SchistMarble
Sedimentary rocks are made of pieces of sediment that have been glued together. The glue for the rocks is made when water dissolves some minerals which later harden. Breccia Conglomerate Sandstone
The rock cycle is continuous and moving in all possible directions.
It takes mechanical energy to move the sediments to form sedimentary rocks. Magma has a tremendous amount of heat to melt minerals together. It requires tremendous heat and pressure to form metamorphic rocks.
Erosion changes the surface of the Earth by wearing away the materials. mudslide water erosion Dust storm
Weathering changes Earth materials. Chemical Mechanical
Soil forms when rock has been weathered and eroded.
Fossils are the remains or traces of ancient life. They are at least 10,000 years old. They can be mineralized samples such as petrified wood. They can be materials from the organism like bones and fur. They can also be traces of the organism like footprints or nests.
Fossils are most commonly formed when: 1. An animal dies and its skeleton settles to the seafloor where it is buried by sediment. 2. The sediment thickens and begins to turn to stone. 3. The skeleton dissolves and a mold is formed. 4. Minerals crystallize inside the mold and a cast is formed. 5. The fossil is exposed on Earth’s surface due to erosion.
Deposition happens when the energy causing the transportation of sediments is unable to move them further. Therefore, they are deposited in an area. Sediments are deposited in layers.
Rocks are dated by relative age. The older rocks are said to be at the bottom, while the younger rocks are normally on the top.
These rocks have been folded In this case the youngest ones may not always be on top.
These rocks have been faulted Again some of the rocks have shifted, so relative age is harder to determine.
Fossils show evidence of the changing surface of the Earth. This fish fossil found in a mountain side is evidence that there was once a water habitat in this area.
Recently deposited fossil layers are more likely to contain fossils resembling existing species than the older rock layers. The fossils in unit O will be closer to the existing species than those in the lower units. M will contain the oldest species.
Energy from Earth’s interior causes changes to Earth’s surface. EarthquakesVolcanoes
The Earth’s rock layer is broken into pieces that are in constant slow motion. From time to time, the pieces lock together, and energy that accumulates between the pieces may be suddenly released. It travels through the Earth in the form of waves. People on the Earth experience an earthquake.
An earthquake is the result of a sudden release of energy in the Earth’s crust that creates seismic waves. These seismic waves transfer mechanical energy.
A volcano is an opening in the Earth’s crust which allows hot magma to escape from below the surface.
A volcano is a release of energy that built below the surface of the Earth due to heat and pressure. Flowing magma transfers heat and mechanical energy.
Small changes over time add up to major changes on Earth’s surface.