Skip this Video
Download Presentation

Loading in 2 Seconds...

play fullscreen
1 / 42

Minerals - PowerPoint PPT Presentation

  • Uploaded on

Minerals. What is a Mineral?. Naturally Occurring. Inorganic. Solid. Definite Chemical Formula. Definite Crystal Structure. Naturally Occurring. Formed by natural processes not in the laboratory. Is an ice cube a mineral?. Is the ice on the windshield of a car a mineral?.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Minerals' - tala

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
what is a mineral
What is a Mineral?
  • Naturally Occurring
  • Inorganic
  • Solid
  • Definite Chemical Formula
  • Definite Crystal Structure
naturally occurring
Naturally Occurring
  • Formed by natural processes not in the laboratory.
  • Is an ice cube a mineral?
  • Is the ice on the windshield of a car a mineral?
  • Minerals manufactured by humans are not considered minerals.
  • Formed by inorganic processes; not living
  • Minerals are not made from living things.
  • Coal is made of carbon. Is it a mineral?
  • Minerals cannot be a gas or a liquid.

- H2O as ice in a glacier is a mineral, but

water is not.

definite crystal structure
Definite Crystal Structure
  • Highly ordered atomic arrangement of atoms in regular geometric patterns
  • Minerals are crystals with a repeated inner structure.





definite chemical formula
Definite Chemical Formula
  • Gold (Au)
  • Calcite (CaCO3)
  • Minerals are expressed by a specific chemical formula.
  • Quartz (SiO2)
  • Pyrite (FeS2)
  • Minerals made of only one type of atom (element) are called native elements.
  • Gold
  • Copper
  • Silver
types of minerals
Types of minerals
  • Minerals are most commonly classified by chemical composition.
  • The 2 main groups are silicates and nonsilicates.
  • Minerals containing a combination of silicon (Si) and oxygen (O) (most common elements in the earth’s crust)
  • Silicate minerals comprise about 90% of the Earth’s crust.
  • Silicates minerals often contain other elements such as aluminum, iron, magnesium, and potassium.
  • Granite is a rock comprised of the minerals feldspar, biotite mica and quartz.
  • Feldspar minerals make up half of the Earth’s crust and is the main component of most of the rocks found on the Earth’s surface.
  • Feldspar contains Si, O, Al, K, Na, and Ca


biotite mica
Biotite Mica
  • Soft and shiny minerals that separate easily into sheets
  • Biotite is one variety of mica
  • Silicon dioxide ( SiO2) is the basic building block of many rocks
  • Minerals that do not contain the combination of Si and O
  • Some of these minerals are made up of C, O, F, and S
classes of nonsilicates
Classes of Nonsilicates
  • Native Elements
  • Carbonates
  • Halides
  • Oxides
  • Sulfates
  • Sulfides
native elements
Native Elements
  • Native elements are composed of only 1 element
  • About 20 exist including Au, Pt, C, Cu, S and Ag
  • Contain the combinations of carbon and Oxygen in their chemical structure
  • Calcite (CaCO3 ) is an example
  • Carbonates are used in cement, building stones and fireworks
  • Form when atoms containing fluorine, chlorine, iodine, or bromine (halogens) combine with potassium or calcium
  • Halite (NaCl) is better known as rock salt
  • Fluorite can have many different colors


  • Halides are often used in making fertilizers
  • Compounds formed when elements like aluminum or iron bond with oxygen
  • Corundum (Al2O3) and Magnetite (Fe3O4) are important oxides
  • Are used in abrasives and airplane parts
  • Minerals containing sulfur and oxygen (SO4)
  • Gypsum (CaSO4 * 2H2O) is a common example
  • makes the white sand at White Sands National Monument in NM


  • Sulfates are commonly used in cosmetics, toothpaste and paints
  • Minerals containing one or more elements such as lead, iron, or nickel combines with sulfur
  • Galena (PbS) is a sulfide
  • Sulfides are used to make batteries, medicines and electronic parts


composition of the earth s crust
Composition of the Earth’s Crust
  • Eight Elements that make up over 98% of Earth’s Crust

- Oxygen (O)

- Silicon (Si)

- Aluminum (Al)

- Iron (Fe)

- Calcium (Ca)

- Sodium (Na)

- Potassium (K)

- Magnesium (Mg)

where do minerals come from
Where Do Minerals Come From?

In general, minerals form in two ways:

Cooling magma - Crystallization of melted materials

From solution - Crystallization of materials dissolved in water


a. At the surface

b. Beneath the surface


  • Magma is molten material from the mantle that hardens to form rock.
  • Lava is magma that reaches the surface.
  • Minerals form as hot magma cools inside the crust, or as lava hardens on the surface.
  • When these liquids cool to the solid state, they form crystals.
size of crystals
Size of Crystals
  • The rate at which the magma cools
  • Depends of several factors:
  • The chemical composition of the magma
  • The amount of gas the magma contains
  • When magma remains deep below the surface, it cools slowly over many thousands of years.
  • Slow cooling leads to the formation of large crystals.
  • Magma closer to the surface cools much faster, producing smaller crystals.
minerals from hot water solutions
Minerals from Hot Water Solutions
  • Sometimes, the elements that form a mineral dissolve in hot water and form a solution.
  • A solution is a mixture in which one substance dissolves in another.
  • When a hot water solution begins to cool, the elements and compounds leave the solution and crystallize as minerals.
  • This can happen on the ocean floor when ocean water seeps down through cracks in the crust.
minerals formed by evaporation
Minerals formed by Evaporation
  • Minerals can also form when solutions evaporate. Example: salt from sea water
  • Several other useful minerals also from by the evaporation of seawater:
  • Gypsum
  • Calcite crystals
  • Minerals containing potassium
minerals formed by metamorphism
Minerals formed by Metamorphism
  • When rocks are put under extreme heat and pressure, the chemical composition of the rock can change, forming new minerals.
  • Examples: calcite, garnet, graphite, hematite, magnetite, mica and talc.
how are minerals identified
How Are Minerals Identified?
  • Luster
  • Color
  • Hardness
  • Streak
  • Density
  • Crystal Shape
  • Cleavage and Fracture
  • Special Properties



  • Not a reliable way to identify a mineral
  • Usually the first and most easily observed

- Some minerals are the same color as others

- Some minerals can have many colors

  • General appearance of a mineral surface in reflected light


examples of luster
Examples of luster
  • Vitreous: similar to glass
  • Metallic
  • Resinous: resembles the way plastic reflects light
  • Pearly: resembles the way pearls shine
  • Greasy: resembles the way petroleum jelly or a greasy surface reflects light
  • Silky: resembles the way silk reflects light
  • Earthy: dull, may be rough or dusty
  • Waxy
  • Adamantine: resembles the way a diamond shines
  • Fibrous – looks like fibers
  • Pitchy – looks like tar
  • Resistance to scratching by different items; “scratchability”
  • Mohs Hardness Scale is used to determine the hardness of minerals by comparing them to substances of known hardness.
mohs mineral hardness scale


Mohs Mineral Hardness Scale


1) Talc

2) Gypsum

3) Calcite

4) Fluorite

5) Apatite

6) Feldspar

7) Quartz

8) Topaz

9) Corundum

10) Diamond










  • The color of a finely powdered mineral
  • Determined by rubbing the mineral on a piece of unglazed porcelain (streak plate)
  • The amount of matter in a given space
  • Specific Gravity is the comparison of a substance’s density to the density of water
crystal shape
Crystal Shape
  • Minerals have a characteristic crystal shape resulting from the atomic packing of the atoms when the mineral is forming
cleavage and fracture


Cleavage and Fracture
  • Cleavage is the tendency of a mineral to split or crack along parallel or flat planes.
  • Fracture occurs when a mineral breaks at random lines instead of at consistent cleavage planes.


1 Direction of Cleavage

No Cleavage

Conchoidal Fracture

special properties
Special Properties
  • Glowing under ultraviolet light (Fluorite)
  • Magnetism (Magnetite)
  • Taste (Halite)
  • Smell (Sulfur)
  • Reaction to HCl (Calcite)
  • Double refractive - a thin, clear piece of calcite placed over an image will cause a double image
  • Radioactivity - minerals containing radium or uranium can be detected by a Geiger counter
economic importance of minerals
Economic Importance of Minerals
  • Minerals are in many things we see and use everyday such as; bricks, glass, cement, plaster, iron, gold
every american requires 40 000 pounds of new minerals per year
Every American Requires 40,000 Pounds of New Minerals per Year

At this level of consumption the average newborn infant will need a lifetime supply of:

- 795 lbs of lead (car batteries, electric components)

- 757 lbs of zinc (to make brass, rubber, paints)

- 1500 lbs of copper (electrical motors, wirings

- 3593 lbs aluminum (soda cans, aircraft)

- 32,700 lbs of iron (kitchen utensils, automobiles, buildings)

- 28,213 lbs of salt (cooking, detergents)

- 1,238,101 lbs of stone, sand, gravel, cement (roads, homes)