SCIENCE 08 GEOLOGY Notebook Page E

EXPERIMENT # 2

IDENTIFYING ROCKS

PROBLEM:

1.To discover some characteristics useful in classifying rocks into families.

2.To identify samples of unknown rocks using these properties.

HYPOTHESIS:

It will be possible to both classify rocks into (how many?) families and to identify those rocks on the basis of

with a predicted accuracy of correct out of twenty samples.

APPARATUS AND MATERIALS:

Loose and mounted samples of the following rocks:(* = 2 samples)

BasaltGabbroLimestone *PumiceSandstoneShale

CoalGneissMarbleQuartzite SchistSiltstone

ConglomerateGranite *ObsidianRhyoliteSea SaltSlate

The following apparatus and materials to test rock properties:

Common nailMagnetCopper penny (dated prior to 2000)

Glass plate Streak plateDilute hydrochloric acid in dropper bottle

PROCEDURE:

For each loose sample provided perform each of the following rock identification tests and enter your observations and test results in Table I:

CAUTION:DO NOT REMOVE ANY SAMPLES FROM THE IDENTIFICATION CARDS. PERFORM ALL TESTS ON THE LOOSE SAMPLES. SAFETY GOGGLES MUST BE WORN TO PREVENT FLYING FRAGMENTS FROM ENTERING THE EYE.!

BE EXTREMELY CAUTIOUS WHEN HANDLING HYDROCHLORIC ACID AS IT IS A STRONG HIGHLY CORROSIVE ACID !

 

Using approprite tests describe each rock in terms of its:

1. Texture (size and variety of its crystals or sediments, smoothness).

2. Colour (including variations)

3. Lustre and sparkliness

4. Density

5. Layering

6 Reaction with hydrochloric acid

7. Special features (Hardness of crystals, magnetism, general appearance, presence of fossils, presence of holes, streak of obvious minerals, etc.)

OBSERVATIONS:

Record your observations for Procedures #1 - 7 in Table I.

EXPERIMENT #2: ROCK IDENTIFICATION Page 2 Notebook Page E

DISCUSSION:

1. In your report write "Refer to Table I. Using a "Rock Identification Chart" and your observations from Table I classify each of the twenty mineral samples as igneous, sedimentary, or metamorphic and record your answers in Table I.

2. What properties and special features were the most useful in classifying the rocks as igneous, sedimentary, or metamorphic ?

3. Considering how they are formed, what is the main factor that determines the size of the crystals in the igneous rock samples ?

4. What are several major differences in the appearance of those igneous rocks that are plutonic compared to those that are volcanic ?

5. Why are some of the volcanic igneous rocks characterized by the presence of holes.

6. What are several properties that most of the sedimentary rocks have in common.

7.What kinds of particles were observed to be present in the sedimentary rock samples ?

8.Wht evidence is there that some of the sedimentary rock samples were formed from the remains of living organisms ?

9. Eight of the rocks on display are members of parent/child pairs. List the four parent/child pairs into which these eight rocks can be grouped.

10. In which parent/child pair is calcite present in both rock samples ? What experimental evidence was there for the presence of calcite in these two rock samples ?

11. State three general differences in the appearance and properties of the child metamorphic rocks compared to their parents.

12. In your report write "Refer to Table I. Using a "Rock Identification Chart" and your observations from Table I identify each of the twenty rock samples by name and record your answers in the extreme right column Table I.

13. Only after completing your predictions compare your predicted identifications to the actual or correct identities of the samples mounted on the large display cards and determine the number of rocks out of twenty that you had correctly identified. Also determine how many rocks you had correctly classified as igneous, sedimentary, or metamorphic. Finally copy from the display cards into Table I the names of the predominant mineral present in each rock sample

CONCLUSION:

Make a judgment statement about your original hypothesis and answer the two questions in the problem. Answer the second problem by listing your predicted identities and classifications in a neat vertical column as follows:

Code Number,Predicted Rock,Correct Rock,Predicted Rock,Correct Rock,

Identity IdentityClassificationClassification
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