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.