Rocks are natural elements that are made of minerals:

  • Some rocks are made of 1 mineral (e.g. marble is made or calcite).

  • Some rocks are made of more than 1 mineral (e.g. granite is made of feldspar, mica and quartz).

We can find rocks in the 3 states: solid (most of them), liquid (petroleum is considered a rock) and gas (natural gas is considered a rock).

Like minerals, different rocks have different properties and uses.



PROPERTIES

Rocks have many different properties. This course we are going to study the basic ones:

  • Color: as most of rocks are made of 2 or more minerals, they usually display many different colors.

  • Lustre: as minerals, rocks can be shiny (anthracite coal) or dull (limestone rocks).

  • Hardness: it depends on the minerals that the rock contains. So, basically, rocks made of soft minerals, will be soft; while rocks made of hard minerals will be hard.



USES

Like minerals, you can find rocks everywhere:

  • Construction: bricks are made of clay; some walls are made of granite; some roof tiles are made of slate (e.g. our school's roof is made of slate).

  • Energy: cars need petroleum; coal can keep us warm in winter.

  • Industry: plastic, paint and fertilizers are made of petroleum.

Time for the videos.

On the first video, you will review some of the previous information.



On the second video, you will watch how granite is transformed.







Time to play. Go to the games section.