Minerals: Building Blocks of Rocks

Minerals Minerals are the pure, naturally occurring building blocks of rocks Minerals are the pure, naturally occurring building blocks of rocks Differences in rocks are due to different minerals Differences in rocks are due to different minerals All minerals are non-living, but a few contain minerals that were living things – example chalk All minerals are non-living, but a few contain minerals that were living things – example chalk Minerals are used in our everyday life Minerals are used in our everyday life

Minerals are Crystals All minerals are pure crystals All minerals are pure crystals Crystals have regular geometric shapes because they are made up of tiny particles connected in a repeating pattern Crystals have regular geometric shapes because they are made up of tiny particles connected in a repeating pattern Cooled slowly = large crystals Cooled slowly = large crystals Cooled rapidly = small crystals Cooled rapidly = small crystals

Identifying Minerals Lustre – shininess of a mineral Lustre – shininess of a mineral Cleavage – describes the way the minerals split into smaller pieces Cleavage – describes the way the minerals split into smaller pieces Hardness – describes how resistant a mineral is to being scratched Hardness – describes how resistant a mineral is to being scratched Colour- describes the appearance of the mineral Colour- describes the appearance of the mineral Not always reliable Not always reliable

Identifying Minerals Streak – the color the minerals leaves behind when ‘streaked’ across unglazed porcelain tile Streak – the color the minerals leaves behind when ‘streaked’ across unglazed porcelain tile Many have to be crushed to powder to determine their streak color Many have to be crushed to powder to determine their streak color Magnetism – 2 minerals, magnetite (strongly) and pyrrhotite (weakly), have magnetic properties Magnetism – 2 minerals, magnetite (strongly) and pyrrhotite (weakly), have magnetic properties Density – mass per unit volume of a substance Density – mass per unit volume of a substance