practical 2 sce 3110

7/30/2019 Practical 2 SCE 3110

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Practical 2SCE 3110

Identifying Rocks

Introductions:

Geologists classify rocks in three groups, according to the major Earth processes that formed them.

The three rock groups are igneous, sedimentary, and metamorphic rocks.

Igneous rocks are crystalline solids which form directly from the cooling of magma. This is an

exothermic process (it loses heat) and involves a phase change from the liquid to the solid state.

In most places on the surface, the igneous rocks which make up the majority of the crust are covered

by a thin veneer of loose sediment, and the rock which is made as layers of this debris get compacted

and cemented together. Sedimentary rocks are called secondary, because they are often the result of

the accumulation of small pieces broken off of pre-existing rocks.

The metamorphic get their name from "meta" (change) and "morph" (form). Any rock can become a

metamorphic rock. All that is required is for the rock to be moved into an environment in which the

minerals which make up the rock become unstable and out of equilibrium with the new

environmental conditions. In most cases, this involves burial which leads to a rise in temperature andpressure. The metamorphic changes in the minerals always move in a direction designed to restore

equilibrium. Common metamorphic rocks include slate, schist, gneiss, and marble.

Apparatus :

1. Weighing

2. Beaker

3. Measuring cylinder

4. Nail

5. Coin

6. dropper

Materials:

1. Different type of rocks

2. Water

3. Sulphuric acid

Procedures:

1. Rocks sample was bring from neighborhood.

2. The different in the rocks was discussed by using content in the table.

3. The densities of the rocks were find using the mass/ volume relationship.

4. From the data collected the name of rocks was defined.

5. The other technique was used to classify or name the rocks.

6. The rocks were tested with sulphuric acid by using the dropper. The surface of the rocks tested

with sulphuric acid was observed.

7. The hardness of the rocks was tested using finger nail, common nail and concrete nail according to

the scale of hardness of the rocks.

8. The volume was measured using measuring cylinder and the weight was measured using weighing.

Data:


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Rock A

Rock B

Rock C

Rock D

Rock E

Data analysis:

In this experiment, 5 samples of rock had best tested. The rocks were collected from different places.

Rocks Place taken

A Hill

B Near the road

C River

D Road

E At field

The rocks had been observed in order to classify them according to their characteristics. The rocks

are classified into three groups, which are igneous, sedimentary, and metamorphic. Each of the rocks

has their own characteristics. So, some laboratory tests were taken place. Chemical and physical tests

were used to test the rocks.

As the results, Rock A is only one sample we can classify for the igneous rock because of the

characteristics. The density of this rock is 2.32 x 10-3. Rock A is white in colour, sparkling, very hard

because by using the scale tested with concrete nail(7.5), it has no layer, the texture is extrusive, no

pattern of this rocks and was tested with acid sulphuric show the reaction occur because present of

carbonate. The presence of bubble on the surface of the stone shows the carbonate is formed.

For Rock B and Rock D, both are classified as sedimentary rock. Both have rough surface and not

react with an acid to form carbonate. No bubbles were formed. Both have more than one colour,

which is black and white. The Rock B and Rock D are hard because I could not scratch with finger or

knife. Rock B has density about 2.075 x 10-3 kg cm-3, while the density of rock D is 2.628 kg cm-3.

Rock C is an example of metamorphic rock. Due to it characteristic, Rock C has black and white

pattern. It is hard rock because it could not be stretch by the finger. It shows no reaction when react

with acid sulphuric. No bubbles were formed. Rock C has layer and the density of Rock C is 2.736 kg

cm-3

Rock E is another igneous rock. It is white in colour. No reaction occur when react with acid sulphuric.It is a shiny rock. There is no pattern on this rock. The rocks density is 1.926 kg cm-3


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Conclusion:

Rocks are classified by studying their characteristic, such as pattern, hardness, reaction with acid,

density, layer and it texture. Rocks are classified into three types, which are igneous, metamorphic

and sedimentary rock.

Igneous rock Sedimentary rock Metamorphic rock

Rock A

Rock E

Rock B

Rock D

Rock C

References:

Book

Lutgen and Tarbuck, (2008). Foundations Of Earth Science , Pearson prentice hall.

Internet

http://www.hf.uio.no/iakh/forskning/sarc/iakh/lithic/rocks.html

http://www.rocks-rock.com/rock-types.html

http://www.zephyrus.co.uk/rocktypes.html

http://jersey.uoregon.edu/~mstrick/AskGeoMan/geoQuerry13.html

http://library.thinkquest.org/20035/newpage8.htm

practical 2 sce 3110

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