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 Form 1 Geography Online Lessons on Minerals and Rocks

In this lesson we are going to learn about the definition of minerals and the characteristics of minerals

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Answer Text:
Minerals and Rocks
Minerals
- Inorganic substances occurring naturally at or below the earth’s surface. Characteristics of Minerals
1. Different degrees of hardness e.g. some are very hard e.g. diamond while others are very soft e.g. talc.
2. Some have atoms arranged in an orderly manner to form crystals e.g. quartz form a 6- sided prism.
3. Varying number of elements e.g. gold has one (Av) while quartz has 2 (SiO2).
4. Different abilities to allow light to pass through e.g. some are transparent, opaque or translucent.
5. Specific colours e.g. gold is shiny yellow while copper is brown.
6. Have specific surface appearance (lustre) when they reflect light i.e. metallic (shiny) or non-metallic (glass like).
7. Definite chemical composition or constant ratio of elements e.g. quartz has one atom of silicon and two atoms of oxygen.
8. Tendency to break along certain lines or cleavage) e.g. flint has cleavage like that of glass.
9. Different densities e.g. some are very heavy e.g. lead while others are light e.g. silicate minerals.
10. Some minerals conduct electricity while others don’t e.g. copper conducts while diamond doesn’t. 11. Some can be pressed into different shapes while others can’t e.g. copper is malleable while flint isn’t.
Types of Minerals
Metallic minerals
Ferrous Minerals - limonite, magnetite, siderite and haematite.
Non-ferrous Minerals - copper, aluminium, gold, lead, etc.
Non-metallic Minerals - graphite, diamond, asbestos, coal, etc.
Energy minerals - petroleum, coal and uranium.


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