1. What are rocks?
There are many different rocks. Usually made up of different mixtures of minerals (solid
compound or elements that are naturally in the ground).
Texture
The texture of a rock describes the way its grains fit together.
There are two main types of texture of rocks:
• Crystalline texture: the mineral grains are crystals in the rock. The grains all interlock.
There are now gaps between the crystals.
• Fragmental texture: the minerals form randomly shaped fragments or grains that do
not fit together neatly. Another mineral often “cements” the grains to each other.
Porosity
The porosity of a rock tells us how well it soaks up water
Rocks that have spaces between their grains can soak up water better than rocks wit
interlocking crystals.