CH. 3MINERALS & ELEMENTS

MINERALS OF THE EARTH’S CRUSTMineral: naturally formed, inorganic

solid with crystalline structure.Characteristics of Minerals:

1. Is it a solid? Minerals can not be gases or liquids.

2. Is it formed in nature? Crystalline materials made by people are not classified as minerals.

3. Is it nonliving material? Minerals are inorganic (made of nonliving things).

4. Does it have a crystalline structure? Minerals are crystals. They have a

repeating inner structure usually with the same composition.

To understand how all of this fits together (structure), you need to know what these are:Atom(s): smallest part of an elementElements: pure substancesCompounds: combination of 2 or more elements

Rocks (more later):

TYPES OF MINERALS

8 Types for our purposes1. Silicates (Si-O)2. Non-Silicates (Si- OR O-…not both)3. Native Elements (Most Metals in P.T.E.

ONE ELEMENT)4. Carbonates (C + O2)

5. Halides (Cl-, F-, Br-, I-…with a metal)6. Sulfates (S + O2)

7. Oxides (Oxygen + a metal)8. Sulfides (Sulfur + a metal)

TYPES OF MINERALS Minerals are divided into two groups by

the elements they are composed of. The groups are:1. Silicate Minerals: (Si-O)

90% + of Earth’s crust because silicon and oxygen are the most common elements in the Earth’s Crust!!

2. Non-silicate Mineral: (Si OR O…not both)

Do not contain A COMBINATION of silicon and oxygen.

Native Elements: composed of only 1 elementEX: gold, diamond, copper, sulfur, silver

Carbonates: contain combination of carbon and oxygenEX: calcite–used in cement, fireworks,

building stonesHalide: compounds that form b/w

flourine, chlorine, iodine bromine w/ sodium, potassium, calciumEX: halite(NaCl)—often used in fertilizers.

Sulfate: contain sulfur and oxygenEX: Gypsum—used in cosmetics,

toothpaste, paintOxides: compounds that form when

elements aluminum/iron combine chemically w/ oxygenEX: corundum, magnetite–used to make

abrasives and aircraft partsSulfides: contain 1 or more elements

(lead, iron, nickel w/ sulfur)EX: galena—used to make batteries,

medicine, electric parts

IDENTIFYING MINERALS

1. Color2. Luster: way a surface reflects light

MetallicSub-metallicNon-metallic:

Vitreous: glassy, brilliantSilky: swirly, fibrousResinous: plasticPearly: creamyEarthy: rough, dull

3. Streak4. Cleavage: to break along flat

surfaces5. Fracture: to break unevenly along

curved/irregular surfacesConchoidal Fracture: Quartz

6. Hardness: Moh’s Hardness Scale1. Talc 6. Orthoclase2. Gypsum 7. Quartz3. Calcite 8. Topaz4. Flourite 9. Corundum5. Apatite 10. Diamond