What is a Mineral? 4 requirements to being identified as a mineral 1. Be a Solid 2. Formed in Nature 3. Have a set Chemical.

http://www.mii.org/www.mii.org

What is a Mineral?What is a Mineral?

What is a Mineral?4 requirements to being identified as a mineral

1. Be a Solid

2. Formed in Nature

3. Have a set Chemical Make-Up

4. Have a Crystalline Structure

• Are formed by natural processes. - Minerals can not be man-made

• Are NOT alive and NEVER were alive. Minerals are inorganic.

• Minerals and Rocks ARE NOT the same thing. Minerals ARE NOT rocks. Minerals are the ingredients that make up rocks.

All Minerals….

Minerals have a set Chemical Make-UpCHEMISTRY

• An element contains only one type of atom

• A compound contains two or more elements chemically combined

• A mixture contains elements and or compounds that are not chemically combined

GEOLOGY

• A Native Element contains only one type of atom and is found naturally on earth in its pure form.

• A mineral contains two or more elements chemically combined

• A rock contains a mixture of elements and compounds

Native Elements Only a few minerals occur as pure elements

in the earth’s crust.

Gold Graphite Silver Sulfur Diamond Copper Platinum

Au C Ag S C Cu Pt

Most are found as Chemical Compounds

Beryl

Be Al Silicate

Quartz SiO2 Calcite CaCO3

Rocks are mixtures of minerals and elements.

Lapis lazuli

• Lazulite

• Calcite

• Pyrites

Granite• Quarts • Feldspar

• Mica

Unakite• Quarts • Feldspar

• Epidote

ORES are rocks containing valuable minerals

Hematite Malachite Galena

Iron Ore Copper Lead

Gold in Quartz

ORES• Gold in W.A. is mined from

tellurides, chlorites, quartz veins and in copper ores at Telfer

• Gold nuggets are native elements.

• Copper is found in cuprite, malachite and azurite

• Native copper is rare

• Iron ores consist of haemetite, magnetite, pyrite and limonite

• Diamond in W.A. is mined from volcanic plugs called Kimberlite pipes.

Crystalline Haemetite is used to make jewellery

General Facts about Minerals

• Between 2 - 3,000 have been identified• A few are “native elements” -- made of

only one element, such as sulfur, gold. copper, and graphite (carbon)

• Most are compounds, especially the silicate group (Si, O).

• Other important groups are oxides, carbonates, and sulfides.

Less than a dozen are common in most rocks

• Quartz• Feldspar (group)• Muscovite (white

mica)• Biotite (black mica)• Calcite• Pyroxene

• Olivine• Amphibole (group)

• Magnetite, limonite, and other iron oxides

• Pyrite

Common uses include:

• Aluminum--packaging, transport, building• Beryllium--gemstones, fluorescent lights• Copper--electric cables, wires, switches• Feldspar--glass and ceramics• Iron--buildings, automobiles, magnets• Calcite--toothpaste, construction

• http://www.mii.org/commonminerals.php

Minerals are identified by their key characteristics

• Color

• Hardness

• Crystal Structure

• Luster

• Streak

• Cleavage/fracture• Density (specific

gravity)• Special Properties

-reaction to acid

-fluorescence

-salty taste

-magnetism

Color

Color is the easiest mineral observation…. BUT it is the least reliable!!!!

-Different types of minerals can have the same color.

-Some minerals (Quarts) can come in a variety of colors.

Mineral Hardness Ability to scratch another mineral

Definite Crystal Structure

• All minerals have a crystal structure.• Highly ordered atomic arrangement of atoms in regular

geometric patterns

Apatite Feldspar Diamond Quartz

Describes how light reflects off the surface

•Main categories are “metallic” and “non-metallic”•Non-metallic includes “dull,” glassy,” waxy,” “pearly,”

StreakColor of the powder when rubbed on a “streak plate”

How a Mineral Breaks

Cleavage: Some minerals split along flat surfaces.

Fracture: Some minerals break unevenly along rough or curved

Special Characteristics--the “Acid Test” Carbonates react

with dilute HCl and other acids by fizzing or bubbling (releasing CO2 gas)

Special Characteristics-- Fluorescence

• Some minerals will glow when placed under short-wave or long-wave ultraviolet rays

• Franklin and Ogdensburg NJ are famous for their fluorescent minerals

http://www.sterlinghill.org/Tour%20information.htm

Special Characteristics--Salty Taste

• DO NOT TASTE MOST MINERALS!

• Halite is the exception--it will taste salty

http://mineral.galleries.com/scripts/item.exe?LIST+Minerals+Halides+Halite

Special Characteristics--Magnetism

• Many iron minerals will produce an invisible magnetic force field

• “Lodestone” was used by Vikings more than 1,000 years ago as compasses

http://www.minerals.net/mineral/oxides/magnetit/magneti4.htm

What makes a mineral a Gemstone?

• There are over two hundred recognised gemstones. Most are minerals and are cut from naturally occurring crystals.

• To qualify as a gem, the specimen should be hard and tough to resist scratching and have beautiful clarity, colour or 'fire'. Value is based on rarity and rare quality.

Groups of Minerals

• Minerals are grouped by the elements they are made of.

Amethyst

Beryl (Emerald) Calcite

Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples

SilicatesSilicates

Contain Contain oxygenoxygen & & silicasilicaThe most The most abundantabundant group of group of mineralsminerals

Quartz, micaQuartz, mica

MICA Quartz

Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples

Non-SilicatesNon-Silicates

Make up only Make up only 5%5% of the of the Earth’s crustEarth’s crustInclude some Include some of the most of the most important important mineralsminerals

iron, copper, iron, copper, gold, silver, gold, silver, diamonds, diamonds, rubiesrubies

Silver

Gold Ruby Iron

Copper

Diamond

Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples

CarbonatesCarbonates Carbon & Carbon & oxygen and oxygen and a positive a positive ion, such as ion, such as calciumcalcium

Calcite Calcite (CaCO(CaCO33))

Calcite with Duftite inclusions

Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples

OxidesOxides Metallic ion Metallic ion and oxygenand oxygen

Hematite Hematite (Fe(Fe22)O)O33

Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples

SulfidesSulfides Sulfur and a Sulfur and a metallic ionmetallic ion

Galena (PbS)Galena (PbS)

Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples

SulfatesSulfates Metallic ion, Metallic ion, Sulfur & Sulfur & oxygenoxygen

Barite Barite (BaSO(BaSO44))

Barite on Calcite BaSo4 / CaCO3

Barite

BaSo4

Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples

Native Native ElementsElements

Single Single elementselements

Gold (Au), Gold (Au), Diamond (C), Diamond (C), Silver (Ag)Silver (Ag)