GEOL102: Minerals Lab

GEOL102: Minerals Lab (online edition)

 

Minerals are the building blocks of the planet Earth. In this lab, you will learn about how minerals are defined, how they are identified based on their physical properties, and how they are classified, based on their compositions.

 

à Defining minerals. What are the 6 criteria that define a mineral?

 

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What is the definition of a rock from this chapter? In YOUR OWN WORDS, describe some differences between a rock and a mineral.

 

 

 

 

 

 

 

 

 

à Mineral Identification. After reading chapter 3, have a look at the YouTube video linked here: https://www.youtube.com/watch?v=KB-2pO7pSK8

The video discusses the following physical properties: color, hardness, luster, cleavage and streak.

 

Is color a useful for identifying minerals? Why or why not?

 

 

 

 

 

What tool is used in the video linked above to determine the hardness of a mineral?

 

Name 3 other tools that you could use to test hardness.

 

 

 

 

Below are a number of important, rock-forming minerals. By clicking on a mineral name, you will be taken to a website with photos and information about that mineral. Explore these links and use the information within to help categorize them based on their properties. Feel free to look for these minerals at other places online. Some great resources include: mindat.org, webmineral.com, and minerals.net. You can also search for 3D models are different mineral crystals on sketchfab.com.

 

Quartz             Biotite             Calcite             Galena             Gypsum           Pyrite               Talc

 

Olivine             Plagioclase      Halite              Orthoclase      Muscovite       Garnet

 

Pyroxene/augite         Kaolinite          Hornblende                 Flourite            Hematite

 

Here are the same minerals linked above, but given in an alphabetized list:

 

 

biotite

calcite

flourite

galena

garnet

gypsum

halite

hematite

hornblende

kaolinite

muscovite

olivine

orthoclase

plagioclase

pyrite

pyroxene

quartz

talc

 

 

• Two of the minerals listed on the previous page have metallic luster? Which are they?

 

 

 

 

• Which of the minerals listed on the previous page have a hardness of 3 or lower (can be scratched by a fingernail)?

 

 

 

 

• Which mineral listed on the previous page produces a red streak?

 

 

 

 

• Which of the minerals listed on the previous page exhibit fracture, instead of cleavage?

 

 

 

 

 

• Three of the minerals listed on the previous page will develop cleavage, instead of fracture, and will cleave in 3 directions, each meeting at 90 degrees. This means that when the mineral breaks, it will tend to form cubes. Which minerals are these?

 

 

 

 

 

• Which mineral listed on the previous page will readily dissolve in water?

 

 

 

 

 

 

 

 

 

 

 

 

Again, using what you have learned about the minerals in the list, match each mineral on the left with the best description on the right.

 

 

1. Garnet ____ green mineral commonly found in basalt

 

1. Orthoclase ____ forms dodecahedral (12-sided) soccer ball-like crystals

 

1. Calcite ____ has the highest specific gravity (similar to density) on the list

 

1. Olivine ____ is a K-feldspar

 

1. Muscovite ____ is made of just Si and O

 

1. Galena ____ reacts with HCl (hydrochloric acid)

 

1. Quartz ____ a mafic mineral with 2 cleavages at ~ 60° and 120°

 

1. Hornblende ____ a felsic mineral with 1 perfect cleavage plane (forms sheets)