Fiery Rocks
The Three Broad Characters of Rock
igneous, metamorphic, sedimentary
Rock formed from sediments that have been pressed together.
sedimentary rock
the gemstone that is the hardest of all known minerals
diamonds
why is coal called a fossil fuel
it was derived from fossilized remains of plants
any hollow space in the earth's crust that has formed naturally that is large enough to fit a person in
cave
A common intrusive rock
granite
A rough crumbly rock used to make glass
sandstone
This is the rarest, most beautiful, and most durable gems.
What are precious stones
The poorest quality of coal, also known as brown coal
lignite
type of rock that forms when molten rock solidifies
igneous
rock formed from mud or clay, often ground up to make bricks
shale
The most common used metal.
iron or steel
The most common type of coal, also known as soft coal.
bituminous coal
name the well known igneous rock that contains quartz, feldspar, and mica.
Granite
Soft white rock formed from the cemented skeletons of microscopic sea animals.
chalk or limestone
metals such as gold, silver, or platinum are known as
precious metals
A hard shiny black coal that is expensive to mine.
anthracite
The individual substances that make up rocks.
Minerals
A rock made of pebbles cemented together.
conglomerate or breccia
any rock containing a metal together with impurities
ore
Two types of coal mining mentioned in the text
surface and underground
the kind of rock in which solution caves usually form
limestone