3.2.2.3 Give examples of the following physical properties of minerals

FOR EXAMPLE: Quartz can be of nearly any color because of slight mineral impurities. Quartz can be cloudy, white, pink, purple, red, black, smoky, orange and brown.

1. color – 6. streak –

2. luster – 7. specific gravity –

3. hardness – 8. taste –

4. cleavage – 9. chemical reagents –

5. fracture – 10. crystal system –

3.3 DETAILED READING – Basic rock types (R.P – 4.2)

Read the following text and fulfill the following task- state which statements are T (TRUE) or F (FALSE):

Geologists recognize three main rock-forming processes, therefore, three principal classes of Earth-forming substances. In the first process, molten rock, or magma, solidifies either to glass or to an aggregate of one or more minerals, or to some combination of glass and minerals; such rocks are termed igneous. Ignis is the Latin word for “fire”; igneous rocks are, in a sense, formed from fire deep inside the Earth. Lava flows and ash falls are good examples. Sedimentary rocks consist of mechanically accumulated fragments of preexisting Earth materials, as well as, chemical or biochemical precipitations from a fluid medium. Sedimentum is the Latin for “a settling”, and sedimentary rocks have had their constituents settle out from the transporting medium, either air or, more generally, water. Such processes take place at the Earth’s surface. Metamorphic rocks include all those rocks whose original minerals or textures, or both have been altered markedly by recrystallization or deformation; metamorphism generally takes place at considerable depth within the Earth. The Greek word meta is translated as “successive” or “change”; a metamorphic rock represents a later configuration of minerals or textures different from those of the original material.

(Barret E., Hunt A. And Milner B.” Earth and Atmosphere”, 1993, Longman)

Fig. 22. Granite – intrusive igneous rock Fig. 23. Marble – metamorphic rock

Fig. 24. Conglomerate – sedimentary rock

1. As there are three main rock-forming processes, three principal classes of rocks exist.

2. Another term for molten rock is magma.

3. In the first process magma melts and becomes new minerals.

4. Igneous is a Latin word for “fire”.

5. Sedimentary rocks consist of accumulated fragments of chemical or biochemical precipitations from a fluid medium.

6. The process of sedimentation takes place inside the Earth’s crust.

7. Metamorphism is a process, which is marked by recrystallization or deformation.

8. The Greek word meta is translated as “successive” or “change”.

9. A metamorphic rock represents a later configuration of minerals or textures different from those of the original material.

10. The main rock types are: volcanic, sedimentary and metamorphic.

4. Listening comprehension

4.1 You will hear a radio science program in which an expert on climate geography talks about weathering of rocks. For questions 1-5, you must read the three possible answers, and decide which one would be the best answer to the question you have heard .

TASK ONE

1.	A	decomposition
	B	disintegration
	C	weathering

2.	A	Chemical weathering
	B	Physical decomposition
	C	Physical weathering

3.	A	Rock failure
	B	Rock fissure
	C	Rock transformation

4.	A	Their roots destroy rocks
	B	Their branches destroy rocks
	C	Their fractures destroy rocks

5.	A	many
	B	a few
	C	few

TASK TWO

Listen to the recording once more. For questions 6-15, complete the notes with the missing information.

6.	Weathering is the process of rock
7.	Temperature changes in deserts and mountains are
8.	As a result of expansion and contraction, rocks
9.	Finally rocks transform into
10.	When water freezes it increases
11.	Rock pieces have varied
12.	Physical weathering is of rocks due to heat and cold.
13.	Chemical weathering means the influence of water, carbon dioxide
14.	Water directs to more complex .
15.	The action of plants is very

4.2 Listen to the following lecture- Minerals: rock components. Fill in the spaces with the missing information. You will hear the lecture twice.

Some rocks can be seen with the naked eye. These particles are (1) _______. These are (2) _______ ______, which have been inorganically formed. They have definite (3) ________ _________- and definite (4)_________ _________. When a rock forms, the chemicals organize themselves into different minerals. There are hundreds of different minerals, but some are more (5) __________ than others. Every rock is made up of a (6) __________ of different minerals. We can divide minerals into (7)_________ broad categories: 1. (8)________________ 2. (9) _____________ (10)_______ is the most common chemical component of the Earth. The most common rock-forming minerals are (11) _________. The simplest mineral of this type is (12) ___________.

It is pure (13) _________. There are metallic elements combined with silica. An example is magnesium-iron silicate called (14) ________. It is the most common mineral of the (15) ___________ crust. The (16) _____crust is rich in (17) ______, so it’s also rich in aluminum silicate, called (18) ________. Compounds containing carbon are called (19) ________. The most important is (20) _________. It is an (21) _________ mineral, because it’s affected by (22) ___________. The silicates contain (23) ________. Because of their chemical nature, these metals are impossible to remove. (24)_______are metals that contain oxygen and are important ore minerals. Examples are (25) _________ and (26) ________. A metal combined with sulfur forms a (27) ________. These include (28) _______ and (29) _________.