WEEK 2 PPTX EARTH SCIWEEK 2 PPTX EARTH SCI

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1. Earth & Life Science MINERALS SIR HENNO BUGTONG

2. Objectives: Module 2: Lesson 1 - Minerals and their Characteristics - Different Properties of Minerals After going through this lesson, you are expected to: Identify the examples of minerals, Explain the different characteristics of minerals, Differentiate minerals based on their properties, Develop awareness on the importance of minerals around us.

3. Minerals and Rocks Minerals are the building blocks of rocks. A mineral is a naturally-occurring, inorganic, homogeneous solid with definite chemical composition and that exhibits a crystalline structure. How is a mineral different from a rock?

4. Characteristics of Minerals A mineral is Naturally-Occurring A mineral should be naturally-occurring with respect to its formation. It should be made by natural processes without the aid of any organism. In the case of laboratory studies, any material that is formed in laboratories or artificial conditions is not considered a mineral.

5. Characteristics of Minerals A mineral is Naturally-Occurring

6. Characteristics of Minerals 2. A mineral is Inorganic It is formed by inorganic processes and does not contain any organic compound. The process to produce a mineral by natural means is extended further by making sure that no organic material ( or what was once part of an organism) be considered a mineral. This would mean that bones, shells, teeth, and other hard parts of an organism are not minerals.

7. Characteristics of Minerals 2. A mineral is Inorganic

8. Characteristics of Minerals 3. A mineral is a homogeneous Solid We should be able to see something that is uniform in appearance and is in the solid state of matter. This property of minerals is very important especially when dealing with materials in other states such as liquids and gases. A mineral should exhibit stability at room temperature, which can only be attained if it is solid.

9. Characteristics of Minerals 3. A mineral is a homogeneous Solid

10. Characteristics of Minerals 4. A mineral has a definite Chemical Composition Most minerals are chemical compounds and can therefore be represented using a fixed or variable chemical formula. Example: A mineral with a fixed chemical formula is quartz (SiO 2 ). This indicates that the mineral quartz contains one silicon atom and two oxygen atoms.

11. Characteristics of Minerals 4. A mineral has a definite Chemical Composition

12. Characteristics of Minerals 5. A mineral has an ordered internal/crystalline structure Minerals look like crystals since the arrangement of their atoms is ordered and repetitive. Atoms of minerals are arranged in an orderly and repeating pattern. NOTE: Knowing whether a material is crystalline or not would require sophisticated methods such as involving the use of X-rays (XRD).

13. Characteristics of Minerals 5. A mineral has an ordered internal/crystalline structure

14. Activity # 1: Minerals Objective: Determine the crystalline structure of a mineral. Materials: magnifying glass (if available), rock salt, iodized salt Procedure: Using a magnifying glass, observe the grains of a rock salt and an iodized salt. Compare the shape of the grains of the rock salt with that of the iodized salt. Draw the shape of the grains for each. Answer this question: What is the shape of the grains?

15. Mineraloids Any material which passes most of the criteria (but not all) we have set can be considered a mineraloid. Most of the time, mineraloids are naturally-occurring, inorganic, homogeneous solids with definite chemical compositions but with no ordered internal structure. Examples of mineraloids are volcanic glass and opal.

16. Mineraloids Examples of mineraloids are volcanic glass and opal.

17. Properties of Minerals 1. Color Color is the property of mineral that is easiest to identify. It is also considered an unreliable property to use in identifying the mineral since slight impurities can affect color. Color is the perceived wavelength of light that bounced off from the material and is detected by our eyes.

18. Properties of Minerals 1. Color Most of the time, composition dictates what color/hue the mineral will take. But for some, the crystalline structure will also play a role. Example:

19. Properties of Minerals 2. Streak It is the color of a mineral in powdered form. Minerals show color differently when ground into fine powder. In most cases, minerals will show streak color equivalent to its normal massive color. But in rare cases, the streak color will differ from its compact form.

20. Properties of Minerals 2. Streak Example:

21. Properties of Minerals 3. Luster It is the behavior of light as it is reflected by the surface of a mineral. It can be: Metallic – minerals that look like metals and are shiny Non-metallic – luster different from metallic ones. - There are many descriptive terms to choose from including pearly (looks like the surface of a pearl), waxy ( like the surface of a candle), vitreous (like clear or stained glass) and silky ( like silk cloth)

22. Properties of Minerals 3. Luster pearly (looks like the surface of a pearl), waxy ( like the surface of a candle), vitreous (like clear or stained glass) and silky ( like silk cloth)

23. Properties of Minerals 3. Luster Example:

24. Properties of Minerals 3. Luster A mineral’s ability to transmit light determines whether it is opaque, translucent, or transparent. Opaque – when the light strikes the object does not pass through. Translucent – when light strikes the object and some light passes through. Transparent – when light strikes and almost all the light will completely pass through.

25. Properties of Minerals 3. Luster

26. Properties of Minerals 4. Hardness It is the resistance of a mineral to scratching. To determine the hardness of a mineral, a comparative hardness scale assigning numerical values to the hardness was made by Friedrich Mohs. The Mohs Hardness Scales assigned 1 to Talc , which is the softest mineral, and 10 to Diamond , which is the hardest mineral.

27. Properties of Minerals Hardness Mineral 1 Talc 2 Gypsum 3 Calcite 4 Fluorite 5 Apatite 6 Feldspar 7 Quartz 8 Topaz 9 Corundum 10 Diamond

28. Properties of Minerals

29. Properties of Minerals 5. Cleavage It is the mineral’s resistance to being broken and fracture. It is exhibited when a mineral breaks and smooth flat surfaces are formed from the breakage. NOTE: The presence of cleavage in mineral is independent of its hardness. Even diamond exhibits cleavage.

30. Properties of Minerals 5. Cleavage

31. Properties of Minerals 6. Tenacity d escribes the mineral’s reaction to stress (breaking or deforming) Brittleness Malleability Ductility Flexible but Inelastic Flexible but Elastic Sectility