Rocks and Minerals
What are rocks made of? What is Lustre? Are there one or two or three minerals in a rock? Is color a good way to identify a mineral?
Well, if you want to find those answers this is the place to be! Throughout this page you will find information about Rocks, Minerals the types of rocks and what you can do to identify minerals.
Minerals
Chemical element. Compound. Naturally occurring. What comes to mind when you hear these words? Well, for me the word mineral comes to mind. A chemical element or compound is what a mineral is. Naturally occurring means made by the earth, not by man. The ways to identify one mineral from another are: Hardness, Lustre, Color, Streak, Crystal Structure, Cleavage and Fracture. Since some minerals look exactly the same without these tests we wouldn't know which is which for example gold and pyrite.
Hardness: A way that scientists identify minerals is by their Hardness. Hardness is a measure of how easily a mineral can be scratched. A German scientist, Friedrich Mohs made a scale of 10 minerals with a hardness value of 1-10 called Mohs Hardness Scale to identify the hardness of a mineral. According to the Mohs Hardness Scale the softest mineral is Talc and the hardest mineral is Diamond.
Lustre: Another way to identify minerals is the Lustre which is the shininess of a mineral. A metallic mineral is when the mineral shines like polished metal. Non metallic is when the mineral does not look like polished metal and is dull. The categories of the non metallic lustre are the following: Adamantine, Glassy, Greasy, Waxy, Pearly and Silky.
Color: One of the least helpful ways scientists use to identify a mineral is by looking at the Color because some minerals like gold and pyrite might be identical in color and are not very easy to identify. This process, even though not very useful is still necessary in the process in identifying a mineral.
Hardness: A way that scientists identify minerals is by their Hardness. Hardness is a measure of how easily a mineral can be scratched. A German scientist, Friedrich Mohs made a scale of 10 minerals with a hardness value of 1-10 called Mohs Hardness Scale to identify the hardness of a mineral. According to the Mohs Hardness Scale the softest mineral is Talc and the hardest mineral is Diamond.
Lustre: Another way to identify minerals is the Lustre which is the shininess of a mineral. A metallic mineral is when the mineral shines like polished metal. Non metallic is when the mineral does not look like polished metal and is dull. The categories of the non metallic lustre are the following: Adamantine, Glassy, Greasy, Waxy, Pearly and Silky.
Color: One of the least helpful ways scientists use to identify a mineral is by looking at the Color because some minerals like gold and pyrite might be identical in color and are not very easy to identify. This process, even though not very useful is still necessary in the process in identifying a mineral.
Streak: Another way to identify the type of mineral is to take a look at the color streak it has. To do this you will need to take the mineral and drag it across a porcelain tile and see what color streak it makes. Some minerals like feldspar don't make any streak at all, which is another clue to their identity.
Crystal Structure: This, like the others is an import physical property of minerals that scientists use to find the differences in two minerals it is called crystal structure. A crystal has straight edges, flat sides and regular angles. There are six major crystal system: Tetragonal, Hexagonal, Orthorhombic, Monoclinic and Triclinic.
Cleavage and Fracture: Cleavage and fracture are what the stone surface looks like when it is broken off. For instance when the mineral is broken and the surface is smooth it means it is cleavage. Im sure what you can guess its called when the rock is broken and it is a rather jagged surface, yes it means the mineral is Fracture.
Rocks
Rocks, their big, small, round, square, some are formed under the surface some are formed above there are so many types but which is which how do I know?
That's easy you can find out here, this part you will learn about the types of rocks what rocks are and much more.
That's easy you can find out here, this part you will learn about the types of rocks what rocks are and much more.
Igneous
Igneous rocks are formed from molten rock or, lava. Some igneous rocks are formed underneath the surface and some are formed above, when they are formed above it is called extrusive and when they are formed below it is called intrusive. When the rock is extrusive the lava will cool quickly resulting in the rock having small minerals, a good example of an igneous extrusive rock is Basalt which has small crystals. Intrusive is a different process, the rock does not go above, it stays under. The magma will dry much slower then when an extrusive rock is made therefore when the rock is formed it will have large crystals such as, Quartz.
Sedimentary
The first step in the making of sedimentary rocks is, erosion (water, wind and ice), this will cause rocks, mud, sand, minerals and plants to break apart into little pieces called sediments. Erosion is also involved in the next step, it carries the sediments to where they will settle (most likely in water). Over time more and more sediments will settle in the same place. Sedimentary rocks can be formed two ways from here, the first way is Compaction. Compaction is when pressure pushes the sediments together forming the rock. Cementation is the second way, when the sediment is soaked the minerals might dissolve forming cement that will hold the minerals together, again forming a sedimentary rock.
Metamorphic
A metamorphic rock can be made from igneous or sedimentary rock. Heat and pressure push one of those rocks deep down into the earth where hot, watery fluids change the rock both physically and chemically. The term foliated means layered, for example gneiss is originally made from granite, gneiss however has layers and all of the color on it is banded together. So if a rock didn't have all the colors banded together it would be non foliated.
The Rock Cycle
This is an image of the rock
cycle which i will explain below.
When the lava dries and becomes an igneous rock it can become both a sedimentary rock and a metamorphic rock. If it becomes a sedimentary rock ,erosion will break it apart into sediments. The sediments will be effected by either compaction or cementation, resulting in the making of a sedimentary rock. If it were to turn into a metamorphic rock then heat and pressure will push it down below the surface. Then hot watery liquids will change it into a metamorphic rock. A metamorphic rock can turn into a sedimentary rock or an igneous rock. If it were to turn into an igneous rock then the rock would melt from all the heat below the earth and it would become magma. Then like all igneous rocks it would either explode from the volcano and dry on land, or it would stay below the earth and dry there, both ways it would become an igneous rock. If it were to turn into a sedimentary rock, erosion would cause it to break apart and become sediments and then compaction and cementation would effect it. Finally it would become a sedimentary rock.
A sedimentary rock could become all three even another sedimentary rock.
cycle which i will explain below.
When the lava dries and becomes an igneous rock it can become both a sedimentary rock and a metamorphic rock. If it becomes a sedimentary rock ,erosion will break it apart into sediments. The sediments will be effected by either compaction or cementation, resulting in the making of a sedimentary rock. If it were to turn into a metamorphic rock then heat and pressure will push it down below the surface. Then hot watery liquids will change it into a metamorphic rock. A metamorphic rock can turn into a sedimentary rock or an igneous rock. If it were to turn into an igneous rock then the rock would melt from all the heat below the earth and it would become magma. Then like all igneous rocks it would either explode from the volcano and dry on land, or it would stay below the earth and dry there, both ways it would become an igneous rock. If it were to turn into a sedimentary rock, erosion would cause it to break apart and become sediments and then compaction and cementation would effect it. Finally it would become a sedimentary rock.
A sedimentary rock could become all three even another sedimentary rock.
It becomes those three rocks