QUESTIONS MINERALS 1. List five characteristics an Earth material must have in o
ID: 233421 • Letter: Q
Question
QUESTIONS
MINERALS
1. List five characteristics an Earth material must have in order to be considered a mineral.
2. (i) What is the chemical composition of the mineral matter secreted by most organisms?
(ii) What is the name of a mineral and a rock that results from this process?
3. What simple chemical test is useful in the identification of the mineral calcite?
4. (i) If an unknown mineral is scratched by Topaz but orthoclase can’t scratch it, what is the hardness of that unknown mineral?
(ii) What is the name of the mineral whose hardness you determined in (i) above?
5. How many cleavage/s do each of the following minerals have?
(i) Muscovite mica (ii) Plagioclase feldspar (iii) Calcite
6. Which physical property is the most diagnostic for the following minerals?
(i) Graphite (ii) Galena (iii) Pyrite
(iv) Hematite (v) Calcite (vi) Talc
(vii) Biotite mica (viii) Magnetite (ix) Olivine
7. Answer the following questions from page 115 of your textbook (Give it some thought): Question #1, 4, 7, 9, and 11
IGNEOUS ROCKS
8. (i) Compare and contrast extrusive and intrusive igneous rocks.
(ii) Give three examples each of extrusive and intrusive rocks.
9. How does the rate of cooling influence crystal size?
10. Explain how the crystals in pegmatites are able to grow so large.
11. How are granite and rhyolite different? In what way are they similar?
12. (i) Define the Bowen’s reaction series.
(ii) Name the mineral that crystalizes first from a cooling magma
(iii) Name the mineral that crystalizes last from a cooling magma
13. Answer the following questions from pages 150-151 of your textbook (Give it some thought): Questions # 2, 10, and 12.
14. (i) List three main gases released during a volcanic eruption.
(ii) What role do gases play in an eruption?
15. Are volcanoes in the Ring of Fire generally described as quiescent or violent? Explain by giving one example that supports your answer.
16. Volcanism at divergent plate boundaries is most often associated with which rock type?
17. At which of the three types of plate boundaries is the greatest quantity of magma generated?
18. Answer the following questions from page 195 of your textbook (Give it some thought): Question #1, 5, and 7.
SEDIMENTARY ROCKS
19. How does the volume of sedimentary rocks in Earth’s crust compare to the volume of igneous and metamorphic rocks?
20. Name one reason why sedimentary rocks are important.
21. (i) List the three basic sedimentary rock categories.
(ii) Name two rocks each for the sedimentary rock categories you name in (i) above.
22. What is the primary basis for distinguishing among detrital rocks?
23. Distinguish between conglomerate and breccia.
24. (i) Define cementation.
(ii) List the three common cements.
(iii) How might each cement type be identified?
25. Answer the following questions from pages 266-267 of your textbook (Give it some thought): Questions #1, 6, 9, and 10.
METAMORPHIC ROCKS
26. What is meant by the statement “Every metamorphic rock has a parent rock”?
27. Why is heat considered the most important agent of metamorphism?
28. (i) Briefly describe three ways in which the mineral grains in a rock develop a preferred orientation (that is, foliation).
(ii) Name two rocks that exhibit this texture.
29. (i) What is meant by nonfoliated texture?
(ii) Name two rocks that exhibit this texture.
30. Compare and contrast marble and quartzite.
31. Name any three national or international landmarks where marble has been used in their making.
32. Answer the following questions from pages 300-301 of your textbook (Give it some thought): Questions #1, 2, 6, and 8.
Explanation / Answer
1)Main characteristics of an earth material to be a mineral: a)physical b) Optical c) chemical properties
a)physical properties: Hardness , density , crystal shape,cleavage,fracture
b)Optical properties : colour,streak,luster,double refraction,fluorescence,transmission of light
c)chemical properties: Isomorphism,polymorphism,pseudomorphism,Acid test, base test
3) the simple chemical test for calcite: place a drop of weak acid like venegar on to the calcite.It will give bubbles.This happens because a reaction causes a little bit of the calcite to break down releasing carbondioxied gas, making the bubbles.
5) cleavages of i) Muscovite mica : perfect basal
ii) plagioclase feldsper : presence of repeated Albite twin striations visible on cleavage surfaces.
iii) calcite : perfect.
6)physical property most diagnostic for the following minerals : i)Graphite : color, streak,slippery feel,specific gravity
ii) Galena : color,luster,specific gravity,streak,cleavage,cubic or octahedral crystals.
iii)pyrite: color,hardness,brittle,greenish black,streak
iv)Hematite : red streak,specific gravity
v)calcite: rhombohedral cleavage,powdered form effervesces weakly in dilute HCL,curved crystal faces and frequent twinning
vi)Talc: feel,color,softness,cleavage
vii)Biotite mica: dark color,perfect cleavage
viii)Magnetite : strongly magnetic,color,streak,octahedral crystal habit
ix) Olivine: green color,vitreous luster,concoidal fracture,granular texture
Igneous rocks:
8)i) Extrusive rocks: When magma reaches the earth surface ,it causes a volcanic eruption.This eruption generates extensive lavaflows. The rocks formed due to solidification of lava are called extrusive rocks. The extrusive rocks are also called as volcanic rocks.
intrusive rocks : Intrusive rocks are formed when magma crystallizes beneath the earth's surface.Depending on the depth of formation ,intrusive rocks are divided in to two groups.1) plutonic rocks 2)hypabyssal rocks
ii)examples of extrusive rocks: basalt, Rhyolite , andesite,obsidian
examples of intrusive rocks : granite , gabbro , diorite , dunite
9) rate of cooling influences the crystal size : As the Igneous rocks are formed by cooling of magma.It can be used to illustrate how the rate at which molten rocks cools affects the size of the crystals that form within the solid rock.
rapid cooling produces small crystals
slower cooling produces larger crystals
10) If the constituent mineral grains exceed several centimeter in size the rock is said to be pegmatitic structure and the rock is pegmatite.The pegmatite structure shows a coarse and very irregular type of crystallizationThis is because they are formed in the final stage of crystallization of magma..
11) granite is an intrusive rocks.rhyolite is a extrusive rocks.They are similar in mineral composition.