Minerals
- Minerals are naturally occurring substances formed by geological processes. They are usually solid and feature a crystal structure as well as specific physical properties and chemical composition.
- Physical properties of minerals include crystal structure, hardness (Mohs scale), lustre (how it reflects light) and color, as well as more complicated properties such as streak, fracture, cleavage and density.
- Mohs scale of hardness measures the ability of minerals to scratch each other. Talc is soft and is listed as 1, diamond is very hard and is measured as 10.
- The way in which a mineral breaks is called CLEAVAGE or FRACTURE
- cleavage - breaks in long flat planes
- fracture - breaks with jagged edges
- A mineral is sometimes made up of just one chemical element but more often it is a compound (mixture) of two or more.
- For example, diamond is made up of just carbon, while fluorite is made up of a compound of calcium and fluorine.
- There are over 4000 different types of minerals.
- Only around 30 of these are commonly found in the Earth's crust.
- Examples of minerals include calcite, gypsum, feldspar, pyrite, gold, quartz and diamond.
- The precious gems ruby and sapphire are varieties of the mineral corundum.
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READ CHAPTER 3 IN YOUR TEXTBOOK AND THEN COMPLETE THE ASSESSMENT QUESTIONS.
UTILIZE THE FLASHCARDS BELOW TO TEST YOUR KNOWLEDGE ON MINERALS...
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Rocks
- Rocks and stones are naturally occurring solids made up of minerals.
- The Earth's crust is made up of rock.
- Rocks have been used by humans for millions of years, from early tools and weapons through to various construction materials.
- There are three different types of rocks based on the way they form, igneous,sedimentary and metamorphic.
- When magma cools and solidifies it forms igneous rock.
- Examples of igneous rocks include granite, basalt, gabbro, obsidian and pumice. More igneous rock facts.
- Sediment deposited over time, often as layers at the bottom of lakes and oceans, forms sedimentary rocks.
- Examples of sedimentary rocks include sandstone, mudstone, flint, greywacke and chalk. More sedimentary rock facts.
- Extreme pressure and heat over time forms metamorphic rocks.
- Examples of metamorphic rocks include marble, quartzite, schist, granulite and slate. More metamorphic rock facts.
- The metamorphic rock marble is formed from the sedimentary rock limestone.
- The metamorphic rock granulite is formed from the igneous rock basalt.
READ CHAPTER 4 - ROCKS - AND COMPLETE THE SECTION ASSESSMENTS AND CHAPTER REVIEW QUESTIONS. THEN TEST YOUR KNOWLEDGE BY UTILIZING THE STUDY TOOLS BELOW...