45
Minerals

Minerals

  • Upload
    yaholo

  • View
    34

  • Download
    4

Embed Size (px)

DESCRIPTION

Minerals. How do we use Earth Materials?. Earth Materials : minerals, rocks, and mineral resources (95% to 100% of objects you use). What is a mineral?. Mineral : a naturally occurring, inorganic, crystalline solid that has a definite chemical composition. - PowerPoint PPT Presentation

Citation preview

Page 1: Minerals

Minerals

Page 2: Minerals

How do we use Earth Materials?

• Earth Materials: minerals, rocks, and mineral resources (95% to 100% of objects you use)

Page 3: Minerals

What is a mineral?• Mineral: a naturally occurring, inorganic,

crystalline solid that has a definite chemical composition.

1. Naturally Occurring: a mineral must be formed by nature and not made by people.

Page 4: Minerals

What is a mineral?2. Inorganic: a mineral CANNOT form from

materials that were once part of a living thing.

Page 5: Minerals

What is a mineral?3. Crystalline solid: a mineral is always a solid, with

its own unique crystal structure.

Page 6: Minerals

What is a mineral?4. Definite Chemical Composition: a mineral always

contains certain elements in definite proportions.

Quartz Gold

Page 7: Minerals
Page 8: Minerals

Mineral or NOT?• Rock salt–AKA Halite–NaCl

Page 9: Minerals

• Beach sand–AKA tiny pieces of Quartz–SiO2

–Crystal shape is a pyramid

Mineral or NOT?

Page 10: Minerals

• Snow–Occurs naturally

Mineral or NOT?

Page 11: Minerals

• An ice cube

Mineral or NOT?

Page 12: Minerals

How are Minerals Related to Rocks?• A rock is any naturally formed solid that is part of

Earth or any other celestial object.–Organic or glassy rocks are NOT minerals.

Page 13: Minerals

How are Minerals Related to Rocks?• There is only a

small number of minerals commonly found in rocks.

Page 14: Minerals
Page 15: Minerals

Mineral Crystal Structure• A mineral’s atomic arrangement is responsible for

many of its chemical and physical properties.

Page 16: Minerals

Silicate Minerals• What two elements, by mass, make up the

greatest percentage of the Earth’s crust?

Page 17: Minerals

These two elements combine to form compounds called silicates.

The mineral Quartz is a type of silicate (SiO4)

Page 18: Minerals

They (Silica and Oxygen) combine in a specific structure called a: Silicon-oxygen tetrahedron.

Page 19: Minerals

Draw this structure below.

O

O

OO

Si

Page 20: Minerals
Page 21: Minerals

Mineral FormationMinerals can form in TWO ways:1. Crystallization of molten material2. Crystallization of materials dissolved in water.

Salt on a stone of the Dead Sea, Israel

Page 22: Minerals

Massive beams of selenite dwarf human explorers in Mexico's Cave of Crystals, deep below the Chihuahuan Desert. Formed over millennia, these crystals are among the largest yet discovered on Earth

Page 23: Minerals
Page 24: Minerals

Mineral Identification• Each mineral has unique properties that can be

used to identify it.1. Color: the easiest test to do on a mineral, but the

least reliable.

Amethyst

Rose QuartzCitrine

Page 25: Minerals

Calcite

Halite

Corundum

Quartz

Page 26: Minerals
Page 27: Minerals

Mineral Identification2. Streak: the color of the powdered mineral• Obtained by rubbing the unknown mineral on a

streak plate (porcelain tile).

The mineral Hematite ALWAYS has a red streak

Page 28: Minerals

One way to tell Fool’s Gold apart from real Gold is by their STREAK.

Real gold has a golden streak

Pyrite has a black or dark green streak

Page 29: Minerals
Page 30: Minerals

Mineral Identification3. Luster: The shine from an unweathered mineral’s

surface–Metallic – shines like a polished piece of metal. –Non-metallic – does NOT shine like a metal.

Page 31: Minerals

Glassy luster in Quartz

Pearly luster in Muscovite

Earthy luster in Hematite

Metallic luster in Pyrite

Metallic luster in Galena

Page 32: Minerals
Page 33: Minerals

Mineral Identification4. Hardness: a mineral’s

resistance to scratching

The hardness of some common items:•Fingernail – 2.5•A Penny – 3.5•Glass – 5.5•A Streak Plate – 6.5

Page 34: Minerals
Page 35: Minerals

Mineral Identification5. Specific Gravity: the density of a mineral

compared to the density of water.

The mineral Galena has a high specific gravity

Page 36: Minerals
Page 37: Minerals

Mineral Identification6. Cleavage: the tendency of a mineral to break

along the zones of weakness• Minerals can have one, two, or several cleavage planes

Mica has ONE cleavage plane

Feldspar has TWO cleavage planes

Halite (salt) has THREE cleavage

planes

Page 38: Minerals
Page 39: Minerals

7. Fracture: a mineral may break along uneven surfaces.

• Mineral has no preferred zones of weakness.

Splintery fracture in Hornblende

Conchoidal fracture in Quartz

Mineral Identification

Page 40: Minerals
Page 41: Minerals

8. Crystal Structure: orderly arrangement of the atoms in the mineral• The geometric shape of a mineral can reflect its

crystal structure.

Mineral Identification

Herkimer Diamonds are quartz crystals that have a unique 18-sided geometric shape.

Page 42: Minerals

Other Ways to Identify Minerals• Acid – Calcite will fizz in weak hydrochloric acid (HCl)

• Magnetism – Magnetite will pick up paper clips / staples.

• Taste – Halite is rock salt and will taste salty.

• Fluorescence – some minerals (mostly forms of calcite) will glow in fluorescent colors under a black (UV) light.

• Double refraction – some clear forms of calcite will make a double image of words.

Page 43: Minerals

Fluorescence of Minerals

Page 44: Minerals

Double Refraction

Page 45: Minerals