1. What occurrence is common to the hydroxides that we studied?
2. What is the general range of specific gravity for the hydroxides?
High to very high
Moderate to high
Low to moderate
3. What is the general range of hardness for the hydroxides (except goethite)?
1 to 3.5
4 to 6.5
7 to 10
4. What economic use is common to the hydroxides that we studied?