One of the most useful diagnostic properties of minerals is hardness measured in Mohs scale. Please watch the following videos and answer the questions below:
http://www.youtube.com/watch?v=9r7C5SD14HwLinks to an external site.
Links to an external site.
1) How much harder is diamond than topaz? The answer can be found in the second video.
2) If a rock can be scratched by a copper penny but not fingernail, suggest a plausible hardness number for the rock in Mohs scale.
3) Find a rock in your backyard, workplace, park, or wherever it is appropriate, and try to determine its possible hardness number or range. Please indicate where you find the rock, and what the luster, overall shape, size, and color of the rock are. Feel free to attach a picture to your post but it is optional. Describe what you have done to the rock and explain how you determine its hardness number (or range).
4) As a chemist I want you to learn some chemistry in this class. Please search the Internet to find resources that appear to be trustworthy to answer the questions: what is diamond made of? Can diamond be burned? Please cite your sources.