Mr May Erik

Page 1 of 4

Mr May Erik

By | April 2013
Page 1 of 4
Assignment 1: Minerals and Rocks

Critical Thinking. Use complete sentences, correct spelling, and the information presented in Chapters 2 and 3 to answer the questions below.

1) Overall, the physical properties of minerals provide a reliable means to identify common minerals. However, certain properties can exhibit a range of characteristics or values making them less useful for identification purposes. Choose three physical properties that might vary considerably between samples of the same mineral and explain why such variability might exist.

Hardness- Kyanite can contain differential hardness in each mineral.

Color- Spahlerite can be many colors including, black, brown, red, green, white, or yellow.

Habit- Pyrite can be massive, cubic, or octahedral

2) Using the information from Table 2.1 (chapter 2) in the text, identify five different materials that you encounter or use on a daily basis and give a possible mineral that could be mined to supply those materials. Can you think of any other considerations other than economic that might prohibit or limit the mining of certain minerals?

Silver, Graphite, Sulfur, Gold, Copper are minerals I use or encounter daily. The rest of the question having to do with a mineral being mined to supply minerals has me confused, this is the only part of question on this assignment I couldn’t figure out, hopefully we will go over it in class.

3) Why are most rock-forming minerals silicates? Also, considering the composition of Earth's crust, do all of the nonsilicate mineral groups make sense chemically? Why or why not?

Most rock forming minerals are silicates because of the abundance of the two elements oxygen and silicon in the crust and mantle, which make up about 90% of the earth’s crust. Not all nonsilicate minerals groups make sense chemically, for instance a nonsilicate would be granite, which is made up of partly quartz, which is in fact a silicate. The non-silicate mineral groups collectively...