What is a mineral?

1. Target 1: I can effectively communicate the 4 components needed for a substance to be classified as a mineral. What is a mineral? It is a naturally occurring, inorganic solid, that has a definite chemical composition, and has an orderly arrangement of atoms.

2. I. What is a mineral? • 1. Naturally occurring – not man-made • 2. Inorganic solid – never alive • 3. Definite chemical composition - made from specific elements or compounds • 4. Orderly arrangement of atoms. Put your own picture here!

3. What is a mineral? • About 4,000 different minerals are found on Earth, but they all share these four characteristics. • Only 8 elements comprise the majority of the minerals.

4. Where are minerals found?

5. What is a mineral? • Glass - can be naturally formed (volcanic glass called obsidian), is a solid, its chemical composition, however, is not always the same, and it does not have a crystalline structure.  Thus, glass is not a mineral. • Ice - is naturally formed, is solid, does have a definite chemical composition that can be expressed by the formula H2O, and does have a definite crystalline structure when solid.  Thus, ice is a mineral, but liquid water is not (since it is not solid). • Halite (salt) - is naturally formed, is solid, does have a definite chemical composition that can be expressed by the formula NaCl, and does have a definite crystalline structure.  Thus halite is a mineral.

6. Target 2: What is the structure of minerals? • All minerals have a crystalline structure. This indicates that the atoms are bonded in particular patterns that are repeated over and over again. • All minerals are crystals.

7. What is the structure of minerals? • All Mineral crystals are arranged in repeating patterns. The pattern can be viewed on the outside on some types of minerals because the crystal formed in an open space.

8. What is the structure of a mineral? • Some mineral crystals form in tight spaces so the crystal shape can’t be seen on the outside of the mineral. • Mini lab

9. Target 3. How do crystals form? • A. Crystals form from Magma • Magma cools and elements or compounds arrange themselves into orderly, repeating patterns. • The type of mineral crystal depends on the type of elements and or compounds present.

10. How do crystals form? • A. Magma cont. - When magma cools slowly, the crystals can be seen with the unaided eye. This is because the elements or compounds have time to move apart and form into larger crystals.

11. How do crystals form? • A. Magma cont. – if magma cools rapidly then the crystals that form will be small or none at all (can’t see crystals).

12. How do crystals form? • B. Crystals from solution – both require thermal energy to make the elements or compounds move • Evaporation. Water evaporates and elements or compoundsthat are left behind bond together • Super saturated solution Toomany elements or compounds in water can bond together to form crystals (Occurs without evaporation). • Crystals lab

13. Crystals

14. Crystals (brainpop) • www. Brainpop.com

15. Crystals • http://www.crystalinks.com/mexicocrystals.html

16. IV. What are silicates? • Silicates are minerals that contain silicon and oxygen and one or more other elements. • Quartz is a silicate and is the most common mineral. • Silicon and oxygen are the basic building blocks for most of the minerals on the Earth’s crust and mantle. Why is this?

17. What are silicates? • This should answer the question! • The crust is made of many types of rocks and hundreds of minerals. These rocks and minerals are made from just 8 elements: • Oxygen (46.6%) • Silicon (27.72%) • Aluminum (8.13%) • Iron (5.00%) • Calcium (3.63%) • Sodium (2.83%) • Potassium (2.70%) • Magnesium (2.09%)

18. What are silicates? • http://gwydir.demon.co.uk/jo/minerals/silicates.htm

19. Target 5. How are minerals identified? • Appearance • Hardness • Luster • Specific Gravity • Streak • Cleavage • Fracture

20. Mineral identification (brainpop) • www.brainpop.com

21. How are minerals identified? • Appearance – Color and overall physical appearance • Appearance is not always reliable. Why?? • Which mineral is worth $5,000?

22. How are minerals identified? • B. Hardness – The measure of how easily a mineral can be scratched • Mohs Scale is used to measure hardness. It lists the hardness of ten minerals. Talc is the softest with a value of one and diamond is the hardest with a value of 10 • Examples of each

23. How are minerals identified?

24. How are minerals identified? • C. Luster – The way a mineral reflects light. • Metallic luster – shine like metal - i.e. chrome, belt buckle • Nonmetallic luster – does not shine like metal • Dull • Pearly • Silky • Glassy -bring in Materials demo. (plastic, etc.)

25. How are minerals identified? • D. Specific Gravity - The ratio of a mineral’s weight compared with the weight of an equal volume of water. • Expressed as a number. • Gold has a specific gravity of 17, which means it is 17 times heavier than water.

26. How are minerals identified? • E. Streak – The color of a mineral when its in a powdered form. • Streak tests are usually done on a porcelain tile. • Can paper be used for a streak test? (think pencils) • Problem solving page 70

27. How are minerals identified? • F. Cleavage – minerals that break along smooth flat surfaces. • Layer of cake? • G. Fracture – minerals that break with uneven, rough, or jagged edges. • Chunk of cake?

28. Mineral identification

29. VI. What are gemstones? • They are minerals! • They are rare! • They are cut and polished to make them look beautiful!

30. Target 4. What is an ore? • It is a substance that contains a useful material that can be mined at a profit • Hematite is the ore that is mined and iron is the useful material. • Bauxite is an ore that contains aluminum.

31. Ore Clip

32. What are vein minerals? • They are minerals that form in the cracks of rocks. • Gold vein