Minerals Objective(s): Distinguish between elemental and compound minerals List the criteria for being considered a mineral List the physical and chemical properties used to identify minerals

DO NOW Which rocks are made from sediment? Which rocks are made from magma? Which rock type can make metamorphic rock? What are rocks made of?

Atoms Building blocks for all materials on Earth 3 components: Protons Neutrons Electrons

Elements Atoms combine to form elements Can’t be broken down by chemical means

Minerals Elements combine to form MINERALS Atoms Elements Minerals

Mineral Criteria Naturally Occurring Inorganic Solid Not man-made Inorganic Not made from living things or the remains of them Solid Definite size and shape Definite Chemical Composition Quartz = SiO2 Crystalline Structure Atoms arranged in repeating patterns

Mineral Formation CRYSTALIZE PRECIPITATE Cooling of molten rock (lava / magma) material PRECIPITATE Evaporation of water with dissolved minerals

Mineral Composition Elemental Compound Composed of only 1 element Composed of 2 or more elements Graphite (C) Copper (Cu) Gold (Au) Diamond (C)

Different Arrangements Identifying Minerals Mineral Properties are determined by their “internal arrangement of atoms” Different Arrangements = Different Properties Graphite Diamond BOTH ARE MADE OF CARBON!

Mineral Properties Physical Properties Chemical Properties Color Streak Luster Hardness Cleavage/Fracture Density Chemical Properties Magnetism Fizzing

DO NOW What criteria defines a mineral? Naturally occurring Inorganic Solid Definite chemical composition Crystalline structure

Physical Properties 1. COLOR Unreliable when used alone!!! Why? Most visible property of a mineral Unreliable when used alone!!! Why? One mineral can have many colors Different minerals have similar colors

Colors of Quartz

STREAK MAY BE DIFFERENT Color of a mineral in its powder form STREAK MAY BE DIFFERENT THAN THE MINERAL COLOR

Varieties of Hematite – all same color streak

How light is reflected off of the surface of a mineral Two types 3. LUSTER How light is reflected off of the surface of a mineral Two types Metallic Shines like brightly polished METAL Non-metallic Glassy, dull, earthy, pearly

Examples of Metallic Luster GALENA PYRITE GRAPHITE

Examples of Non-Metallic Luster QUARTZ FELDSPAR

THE SOFTER THE MINERAL, THE EASIER IT IS TO SCRATCH 4. HARDNESS The resistance ability of a mineral when scratched THE SOFTER THE MINERAL, THE EASIER IT IS TO SCRATCH Higher numbers will scratch lower numbers

Physical Properties 5. CLEAVAGE AND FRACTURE Cleavage Fracture Breaks in a pattern Fracture Splits unevenly into irregular pieces with rough and jagged edges

Cleavage – due to weak bonds in the crystal structure Halite (NaCl) Fluorite (CaF2) HALITE FLUORITE

MUSCOVITE BIOTITE

Rose Quartz – Conchoidal Fracture

Conchoidal Fracture - Quartz Obsidian

Chemical Properties MAGNETISM Magnetic elements found within magnetite Ex – Iron (Fe) in Magnetite

CAN TELL THE DIFFERENCE BETWEEN HALITE AND CALCITE 2. Fizzing with HCl (Hydrochloric Acid) Some minerals react with acid to form bubbles Ex – Calcite and Dolomite CAN TELL THE DIFFERENCE BETWEEN HALITE AND CALCITE

The diagram below shows a method for determining a physical property of a mineral. The results are shown for two minerals, galena and calcite. Which property of the galena and calcite is indicated by the color of the powder each leaves on the ceramic tile? (1) streak (2) hardness (3) reaction to an acid (4) reaction to a solvent

The diagram below shows a penny scratching the surface of the mineral calcite. Which physical property of the calcite is being tested? (1) streak (3) melting point (2) hardness (4) reaction to acid

A chemical property of a mineral is evident if the mineral (1) breaks easily when struck with a hammer (2) bubbles when acid is placed on it (3) is easily scratched by a fingernail (4) reflects light from its surface