Post on 15-Jan-2016
description
1
Mineral & Rock
2
Composition of the Earth
3
Element• An element is a substance that cannot be
separated into simpler substances by ordinary chemical means.
• The smallest part of an element that has all the properties of that element is an atom.
4
Mineral• A mineral is a naturally occurring
• inorganic
• solid
• definite chemical composition
• crystal structure.
**It must have all five of the characteristics described in this definition.**
5
Rocks• A rock is a hard substance composed of
one or more minerals.
• A rock can also be made of or contain naturally occurring substances that do not perfectly fit the definition of a mineral.
• Rocks can be composed of volcanic glass or of opal. Both of these substances lack a crystalline structure.
6
Rocks• หิ�นออบซี�เดี�ยน (Obsidian)
• SiO2 ที่� มี�มีลที่�นสู�ง(impurities )
7
Bonding• Ionic bond
• Covalent bond
• Metal bond
8
Lattices• Atoms in crystals form a repeating pattern
called a Lattice
9
Identifying Minerals
Color -Sometimes Distinctive
• Often Unreliable
• Affected By:– Chemical Impurities – Surface Coating – Grain Size – Weathering Fluorite
10
Identifying Minerals (Continued)
We Need Properties Directly Linked to Atomic Structure:
• Hardness• Streak• Density• Luster• Cleavage• Crystal Form
11
สี�ผงละเอี�ยด (Streak) ขี�ดบนแผ�นกระเบ��อีงที่��ไม่�เคล�อีบ หร�อี แผ�นขี�ดสี�(streak plate)
แร�ฮี�ม่าไที่ต์�
สี�น��าต์าลแดง
สี�ด�า
แคลโคไพไรต์�
ไพโรล�ไซต์�
สี�ขีาว
ที่$ลก� ฟล�อีอีไรต์�
สี�เหล�อีง
อีอีร�พ&เม่นต์�
ซ$ลเฟอีร�
12
Hardness•Resistance to Scratching •Directly related to relative strength of atomic bonds
•Scratch Test (Mohs)•Indentation Test (Knoop)
13
HardnessTalc
Gypsum
Calcite
Fluorite
Apatite
Feldspar
Quartz
Topaz
Corundum
Diamond
4
2
3
6
5
1
7
8
9
10
14
Mohs vs. Knoop Scales
1. Talc: very small 2. Gypsum, Fingernail: 30 3. Calcite, Penny: 135 4. Fluorite: 163
5. Apatite: knife 430 6. Feldspar, Glass: 560 7. Quartz: 820 8. Topaz: 1340 9. Corundum: 2100 10. Diamond: 7000
15
Mohs and Knoop scale
http://www.themeter.net/durezza_e.htm
16
DensityAluminum: 2.7Pyrite, Hematite, Magnetite: 5.0Galena: 7.5Iron: 7.9Copper: 9Lead: 11.4Mercury: 13.6Uranium: 19Gold: 19.3Platinum: 21.4Iridium: 22.4 (densest material on Earth)
17
Luster• Metallic or Nonmetallic is the most
important distinction
• Resinous, waxy, silky, etc. are self-explanatory.
• Vitreous is often used for glassy luster
18 ควอีต์ซ� วาว
แก'ว กาล�นา วาวโลหะ
ความ่วาว (Luster)เป็)นล$กษณะที่��สีาม่ารถพบได'บนผ&วแร�เน��อีงจากการต์กกระที่บและเก&ดการสีะที่'อีนขีอีงแสีง
แสีงต์กกระที่บ
แสีงสีะที่'อีน
วาวแบบอีโลหะ (Non - metallic
luster)
วาวแบบโลหะ
(Metallic luster)
19
แนวแต์กเร�ยบ (Cleavage)
ไม่กา
เป็)นล$กษณะรอียแต์กขีอีงแร�ที่��เก&ดขี��นในแนว ระนาบเร�ยบเน��อีงจากโครงสีร'างอีะต์อีม่ภายในผล0ก
รอียแต์ก แบบน��จะขีนานไป็ต์าม่ผ&วหน'าขีอีงแร�
อีอีร�โที่เคลสี
กาล�นา ฟล�อีอีไรต์�
แคลไซต์�
20
รอียแต์ก (Fracture) รอียแต์กขีอีงแร�ที่��ไม่�ม่�ที่&ศที่างแน�นอีน และพ��นผ&ว
รอียแต์กไม่�เป็)นระนาบเร�ยบ แต์�ม่�ล$กษณะต์�างๆ ก$น 1 รอียแต์กโค'งเว'า
(Conchoidal) 2. รอียแต์กแบบ
เสี��ยน (Splintery) 3. รอียแต์กหย$ก
แหลม่ (Hackly)
4. รอียแต์ก ขีร4ขีระ
(Uneven)
5. รอียแต์ก เร�ยบ (Even)
ควอีต์ซ� ย&ป็ซ$ม่
ที่อีงแดง
โรโดโครไซต์� คาลซ&โดน�
21
Crystal Form• Takes Luck & Practice
• Well-formed crystals are uncommon
• Crystal Classification is somewhat subtle
• From solutions, melts, and vapors
• Evaporation of solvent, cooling, reduction of pressure
22
Precipitation of crystals from vapor
23
The Crystal Classes
24
25
Geologic Setting •Some minerals occur in all geologic
settings: quartz, feldspar, pyrite
•Some minerals occur mostly in sedimentary settings: calcite, dolomite
•Some minerals occur mostly in igneous settings: olivine
•Some minerals occur mostly in metamorphic settings: garnet, kyanite
26
Special PropertiesSome minerals can be identified by
special properties.
• Magnetite is naturally magnetic.
• Fluorite glows under ultraviolet light.
• Halite tastes salty.
• Sulfur smells like rotten eggs.
• Calcite fizzes when hydrochloric acid is added to .
• Uraninite is radioactive.
27
Minerals By Class• Minerals can be organized, mainly
according to their chemistry
28
Minerals By Class(1)Elements Class: The Metals and their alloys and the Nonmetals. Sulfides Class: The Sulfides, the Selenides, the Tellurides, the Arsenides, the Antimonides, the Bismuthinides and the Sulfosalts. Halides Class: The Fluorides, the Chlorides and the Iodides. Oxides Class: The Oxides and the Hydroxides. Carbonates Class: The Carbonates, the Nitrates and the
Borates.
29
Minerals By Class(2)
Sulfates Class: The Sulfates, the Sulfites, the Chromates, the Molybdates, the Selenates, the Selenites, the Tellurates, the Tellurites and the Tungstates (or the Wolframates).
Phosphates Class: The Phosphates, the Arsenates, the Vanadates and the Antimonates.
Silicates Class: The Silicates (the largest class). The Organics Class: The "Minerals" composed of organic chemicals! The Mineraloids: The "Minerals" that lack crystal structure!
30
Major Mineral Suites
Elements
Metallic:Au, Ag, Cu
• Not Al, Pb, Zn, Fe, etc.
Nonmetallic: C - Diamond, Graphite
• Sulfur
31
Major Mineral Suites
SULFIDES: Dense, Usually MetallicMany Major Ores
• Pyrite FeS2
• Chalcopyrite CuFeS2
• Galena PbS
• Sphalerite ZnS2
• Molybdenite MoS2
Major Cause of Acid Rain
32
Major Mineral Suites
HALIDES: Usually Soft, Often Soluble
• Halite NaCl
• Fluorite CaF2
SULFATES: Soft, Light Color
• Gypsum CaSO4
• Barite BaSO4
33
Major Mineral Suites
OXIDES: Often Variable, Some Ores
• Hematite Fe2O3
• Bauxite Al(OH) 3 (a hydroxide)
• Corundum Al2O3 (Ruby, Sapphire)
CARBONATES: Fizz in Acid, Give off CO2
• Calcite CaCO3
• Dolomite CaMg (CO3)2
34
Carbonates
• Principal Components of limestone and dolostone
• Storehouse for CO2
35
Oxide: Hematite
36
Hydroxide: Bauxite
37
Most Important Mineral Suites :
The Silicate Minerals
• Si + O = 75% of Crust
• Silicates make up 95% + of all Rocks
• SiO4: -4 charge
• Link Corner-To-Corner by Sharing Oxygen atoms
38
Silica Structures
39
Asbestos
40
Silicates
41
Tectosilicates - 3-D Networks
• Quartz Feldspars
42
Quartz
43
Reference• http://mineral.galleries.com/minerals/
by_class.htm
• http://www.johnbetts-fineminerals.
com/jhbnyc/minname.htm
• http://www.geo.sc.chula.ac.th/
Knowledge/Rock%20and%20Mineral.
htm