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-Up CHEMISTRY 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 SiO 2 Calcite CaCO 3

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

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 ApatiteFeldsparDiamondQuartz

Describes how light reflects off the surface Main categories are “metallic” and “non-metallic” Non-metallic includes “dull,” glassy,” waxy,” “pearly,”

Streak Color 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

Special Characteristics-- Salty Taste DO NOT TASTE MOST MINERALS! Halite is the exception--it will taste salty

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

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 Group CharacteristicsExamples Silicates Contain oxygen & silica Contain oxygen & silica The most abundant group of minerals The most abundant group of minerals Quartz, mica MICA Quartz

Mineral Group CharacteristicsExamples Non-Silicates Make up only 5% of the Earth’s crust Make up only 5% of the Earth’s crust Include some of the most important minerals Include some of the most important minerals iron, copper, gold, silver, diamonds, rubies Silver Gold Ruby Iron Copper Diamond

Mineral Group CharacteristicsExamples Carbonates Carbon & oxygen and a positive ion, such as calcium Carbon & oxygen and a positive ion, such as calcium Calcite (CaCO 3 ) Calcite with Duftite inclusions

Mineral Group CharacteristicsExamples Oxides  Metallic ion and oxygen Hematite (Fe 2 )O 3

Mineral Group CharacteristicsExamples Sulfides  Sulfur and a metallic ion Galena (PbS)

Mineral Group CharacteristicsExamples Sulfates  Metallic ion, Sulfur & oxygen Barite (BaSO 4 ) Barite on Calcite BaSo4 / CaCO3 Barite BaSo4

Mineral Group CharacteristicsExamples Native Elements  Single elements Gold (Au), Diamond (C), Silver (Ag)