LESSON 7: THE SOLID PART OF THE EARTH
Minerals and Rocks
Pg. 113 – Rocks constitute the solid part of our planet.
Pg. 114 – Minerals are solid inorganic bodies that have natural origins, defined chemical compositions, and, for the most part, a crystalline structure.
Pg. 118 – Rocks are aggregates of one or more minerals.
Pg. 119 – The collection of processes that generate changes in the composition and in the appearance of rocks is called metamorphism. Generally, occurs in the Earth’s interior and it always takes place in solid rock.
Pg. 124 – We call the Law of Mineral Deposits the proportion of metal sought that is present in the deposit.
Pg. 131 – The Earth’s crust is the thin layer of rocks that cover the surface of the Earth over the mantle.
Activities
1) Could you say that water is a mineral? Explain your answer.
2) Are artificial diamonds (cubic zirconias) minerals? Why?
4) What does it mean that most minerals are compounds? Cite some examples.
6) Some minerals allow us to see objects through them, others only allow light to pass through them, and the majority impede us from seeing through them. With what description would you define each one of these minerals?
8) What metal is extracted from galena? And from blende?
9) How could you obtain aluminium from a mineral?
10) Explain the uses of the following minerals: gypsum, hematite, cinnabar (cinnabarite), and silver.
12) What relation exists between rocks and minerals?
14) Explain why it is correct to say that all rocks are formed from minerals.
20) How are igneous rocks formed? How are they classified?
23) What is metamorphism? Look up information about the origins of marble, slate, and quartzite.
25) What are the minerals cited in the last activity used for?
31) Do you think that gravel alters the environment in a negative way?
36) Elaborate a comparative table of the characteristics of the continental crust and the oceanic crust.
37) Where do you think that the crust is thicker: in the Himalayas, on the floor of the Atlantic Ocean, or in the center of Europe?
41) What are the layers that form the Earth? Briefly describe them.
Clear Ideas
· Minerals are solid inorganic bodies that have a natural origin, a defined chemical composition, and for the most part, a crystalline structure.
· Hardness, luster, color, streak, transparency, cleavage, and magnetism are properties of minerals that allow us to classify them.
· Minerals constitute the core of useful metals for human beings. They are the prime matter used to make useful substances and they are used in jewelry.
· Rocks, the minerals that form the solid part of the Earth, are aggregates of one or more minerals.
· Sedimentary rocks come from the compaction of sediment accumulated on the floor of sedimentary basins.
· Magmatic or igneous rocks come from the cooling of magma. They can be plutonic, if the cooling occurs in the Earth’s interior, or volcanic, if the cooling happens on the Earth’s exterior.
· Metamorphic rocks are formed in zones where rocks are subjected to large amounts of pressure and elevated temperatures, which alter the composition of the minerals without melting the rocks.
· Rocks are used to make construction materials and as ornamental elements.
· We call the Law of Mineral Deposits the proportion of metal sought that is present in the deposit.
· Minerals and rocks are extracted through two ways: interior mining and open air mining.
· The Earth is formed of three layers: the crust, the mantle, and the core. The Earth’s crust is the thin layer of rocks that cover the surface of the Earth over the mantle. There are two types: continental crust and oceanic crust.
· The lithosphere is the most external rocky solid layer of the Earth and is formed by the crust and the external layer of the higher mantle.