MINERALS
MINERALS
A mineral is a chemical element or compound that is naturally occurring and has a crystal structure. A rock is a natural material that is made of one or more minerals and could be made up of one or more element. Some minerals come from inside the earth. Fossil fuel is coal, oil, and gas.
CRYSTAL STRUCTURES
There are six types of Crystal Structures. Some crystals are not visible because they are to small. Scientists use a Moh’s hardness scale to measure how hard the rock is and there are ten levels to the scale.
LUSTER
A luster is how shiny the minerals appear. The shiniest of minerals depends on how light is reflected from it’s surface. If a mineral shines like a polished metal surface then it has a metallic luster.
COLOR
Color is one of the most attractive parts of a mineral. Minerals have different colors and we can’t identify minerals on color alone because some minerals might be the same color. The shiniest of minerals depends on how light is reflected from it’s surface.
CLEAVAGE AND FRACTURE
If you break mineral and it breaks in layers than that’s called Cleavage and if you break another mineral and it breaks in bits and pieces then it’s called Fracture. Not all minerals have Cleavage. Minerals that break rough or jagged edges have fracture. Mica has a single cleavage direction, which allows it to be pulled apart in skinny sheets.
STREAK
A Streak is a mark left on a porcelain tile. The streak comes from the powder of the mineral. A streak test is one way to identify a mineral. A porcelain tile has a hardness value of seven. Some minerals that have a hardness of seven or greater will not leave a streak on the porcelain tile. Graphite is a mineral used on a pencil. Hematite can possibly be dark red, grey, or silverly in color.
MOH'S HARDNESS SCALE
Hardness is a another important part of a mineral. Hardness means sure of the minerals resistance to being scratched. Diamond is the hardest type of rock and cannot be scratched because it is number 10 and the mohs hardness scale is ratings is out of ten and the softest is the pencil point as can be scratches very very easily.
ROCKS
IGNEOUS
Igneous rocks are formed when hot magma or lava cools and becomes solid. Magama is melted rock found deep below earths crust were temperatures and presures are high. Igneous rocks can cool slowly or quickly. The size of the crystls in igneous rocks differs, depending on how quickly the rock cooled.