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.
Date: 2015-10-07; view: 407.
Give examples of the following physical properties of minerals
Match the terms with their corresponding definition.
State what are the synonyms to the following words. Pay attention to the meaning of the word in the text.
| 1. guideline | |
| 2. consistent | |
| 3. value | |
| 4. assist in | |
| 5. be obtained by | |
| 6. unglazed | |
| 7. lattice | |
| 8. be bonded in | |
| 9. random | |
| 10. orientation | |
| 11. chipped edges | |
| 12. distinctive | |
| 13. facilitate | |
| 14. counter |
| 1. hardness | a. its weight relative to the weight of an unequal volume of water |
| 2. habit | b. how a mineral reflects light |
| 3. mineral | c. how a mineral parts along weaknesses in its crystal lattice |
| 4. polymorph | d. random breakage of a mineral along no particular orientation |
| 5. specific gravity | e. a consistent crystal shape, which is controlled by the chemical composition of a mineral |
| 6.conchoidal fracture | f. its color in the powered form |
| 7. luster | g. naturally occurring inorganic substances with a definite chemical composition and specific crystal structure |
| 8. fracture | h. several physical forms of a mineral |
| 9. cleavage | i. how a mineral resists scratching |
| 10. streak | j. minerals break along characteristic curved surfaces that look like slightly concave, circular seashells |
1. color –
2. luster –
3. hardness –
4. cleavage –
5. fracture –
6. streak –
7. specific gravity –
8. taste –
9. chemical reagents –
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)
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| Fig. 21 Conchoidal fracture | | | Fig. 24 Conglomerate – sedimentary rock |