Why that rock was used for that purpose

In this week’s reading and in the power point lecture, you learned about the 3 different rock types in nature: igneous, metamorphic, and sedimentary.  You also learned that rocks are the origin of many important resources humans use on a daily basis.

For this discussion activity I want you to become more aware of the rocks that play a part in your lives.  I would like everybody to find two different types of rocks that you run into on a semi regular basis.  When you start looking, I think you find there are ample examples.  After you have identified what type of rock it is, I would like an explanation of why that rock was used for that purpose, and if other materials would be better.  For example, just looking out of my window I can see granite that is used as erosion protection in a a ditch.

This is a very good use for this rock because it is so hard and resistant to weathering.  On the other hand, I have seen many marble tombstones in Savannah cemeteries.  These headstones are typically badly eroded due to rainwater being slightly acidic.  This is not a particularly good use for this rock because it is not very weather resistant.