1
Name the two types of Igneous rock
Obsidian and Pumice
The hardest of all known materials is the ____.
diamond
Name the two types of sedimentary rock
limestone and Conglomerate
The most commonly used metal is ____.
iron
Name the two types of metamorphic rock
marble and slate
The rarest, most beautiful and durable gems are the ________.
precious stones
Any rock containing a metal together with impurities are called an __.
ore