Name______

Properties of Common Rock Forming Minerals

Introduction

The crust of the Earth is made up of rocks which in turn are made up of over 2000 naturally occurring chemical elements and compounds that we call minerals. Only a small number of these make up the vast majority of the rocks. These are called the common rock forming minerals. This activity is designed to help you practice your ability to understand and analyze information or “scientific data”.

Procedure

The table below provides a great deal of information about some of these “common rock forming” minerals. Use the information in the table below along with your ESRT to answer the questions. Read the questions carefully and make sure that you are answering what is being asked. Mineral hardness is a measure of how difficult it is to scratch the surface of the mineral. Density is a comparative measure of the mass of a certain volume of the mineral, measuring how tightly packed the molecules are. Cleavage planes are the flat surfaces that result when a mineral is broken.

Data Table

Mineral / Approximate Hardness (Moh’s Scale) / Density / Number of Cleavage Planes
Potassium Feldspar / 6.0 / 2.6 / 2
Quartz / 7.0 / 2.6 / None
Calcite / 3.0 / 2.3 / 3
Muscovite Mica / 2.0 / 2.9 / 1
Selenite Gypsum / 2.0 / 2.3 / 1
Amphibole (Hornblende) / 5.5 / 3.1 / 2
Olivine / 6.5 / 3.3 / None
Galena / 2.5 / 7.6 / 4
Pyroxene / 5.0 / 3.2 / 2
Fluorite / 4.0 / 3.1 / 1
Halite / 2.5 / 2.3 / 3

Questions

1.  ______Which mineral has the greatest density?

2.  ______Which mineral has the lowest density?

3.  ______Which mineral is the hardest?

4.  ______Which mineral is the softest?

5.  ______How many minerals have a hardness greater than Amphibole?

6.  ______How many minerals have fewer cleavage planes than Potassium Feldspar?

7.  ______How many minerals have densities greater than that of Quartz?

8.  ______How many minerals have a hardness less than Fluorite?

9.  ______Which minerals has a hardness value half that of Galena?

10.  ______Which mineral has a hardness value 3 times greater than

Muscovite Mica?

11.  ______How many minerals would be scratched by Fluorite?

12.  ______How many minerals would scratch Pyroxene?

13.  ______Name one mineral that would scratch Olivine?

14.  ______Name one mineral that would be scratched by Halite?

15.  ______How many minerals are Silicates (contain both Silicon and Oxygen)?

16.  ______How many minerals contain Magnesium or Aluminum?

17.  ______Which minerals have cubic cleavage?

18.  ______Which mineral bubbles with acid?

19.  ______Which mineral will scratch pyroxene but is less dense than it, and it has

cleavage.

20.  ______Which mineral is softer than Amphibole and contains Potassium.

Conclusion Do the Crossword Puzzle Below.

MINERALS

Across

1. Breaking of a mineral along irregular surface

5. Flat surfaces that result when a mineral is broken

6. Name of person who invented hardness scale

8. Naturally occurring inorganic solid

9. Ability of a mineral to resist scratching

Down

2. Mineral that fizzes with acid

3. The most abundant element in Earth's crust

4. A shiny luster

5. Easily noticed property that is unreliable in identification

7. Color of the powder from a mineral