1. A mineral is classified as an ore as long as_______ a. it's rare and valuable b.it can be used for jewelry c.it's profitable and useful d.it's solid and natural.
2. Titanium ores can occur as_____ a. vein mineral deposits b. beach sands c.magma-formed rocks d.all of the above.
3. Crystals may be______ a.cubic b.monoclinic c.tetragonal d.all of these.
4.Most common rock-forming minerals are_______ a.gems b.ores c.silicates d.oxides.
5.A salt crystal is ______ in shape. a.cubic b.hexagonal c.tetragonal d.monoclinic.