8 12 2015 minerals defined & properties revised

UNPACKED ELEMENT DRIVING INSTRUCTION:

S6E5b:Look into the role of minerals to rock makeup.

INTRODUCTION/ DIRECTIONS

Welcome Junior Geologist today we will find out if an object is a rock or mineral!

Your task is to gather as much information about minerals. You must

copy the information in RED but you are not limited to just that (You may gather more information as needed) that is up to you)

LEARNING GOALS

1. Identify properties of minerals and be able to identify certain minerals using specific tests.

2. Apply Moh’s hardness scale to identify minerals.

Question: What methods can we use to identify minerals?

Minerals are most often identified by inspecting their PHYSICAL and

Chemical properties.

READ ONLY

READ ONLY

READ ONLY

Any substance that contains only one kind of atom that cannot be separated.

A COMPOUND IS…

A substance made from two or more different elements that have been chemically combined.

WHAT IS A MINERAL...

SolidNaturally OccurringInorganicFixed composition, chemical formula

Crystal Structure Form

MINERAL CRYSTALS : A VARIETY OF SHAPES

WHICH REFLECT THE ORDERLY INTERNAL ARRANGEMENT OF ATOMS., IONS, OR MOLECULES CHEMICALLY BONDED.

THE MINERAL GALENA HAS CUBIC CRYSTALS.

Minerals are elements or compounds that are found naturally in rocks or soil.All minerals share certain characteristics and have these things in common:Minerals are not found as liquids or gases. They

are all solids.Minerals form naturally. They are not created by people.Minerals form an orderly, repetitive arrangement. The atoms that minerals are made are connected to each other in a pattern. Fluorite often forms beautiful cube-shaped crystals.Each mineral has a unique chemical composition which also means it has its own chemical formula. The chemical formula for fluorite is CaF2 (calcium fluoride).

PROPERTIES OF

MINERALS

USE THE NEXT SLIDES TO ANSWER THE BOTTOM HALF OF THE

PAPER

GEOLOGISTS USE CHARACTERISTICS

TO TELL ONE MINERAL FROM ANOTHER

MINERALS ARE IDENTIFIED BY THEIR KEY

CHARACTERISTICS: USE THE NEXT SLIDES (RED WRITING) TO FILL IN THE ORGANIZER.

1. hardness

2. crystal shape (form)

3. luster

4. color5. streak

6. cleavage/fracture

7. density (specific gravity)

special properties --reaction to acid --fluorescence --salty taste --magnetism

HARDNESS:Is measured by how easy

it is to scratch. By using Moh’s Scale of Hardness

Geologists order the hardness by…

1.Scratched by a fingernail.2.Scratched by a penny. 3.Scratched by a nail. 4.Scratched by a diamond. These are not all of the tools

geologists use,

Mohs Scale of Hardness

Hardest (10) – Diamond

Softest (1) – Talc

Common objects:

- Fingernail (2.5) - Copper penny (3.5) - Wire nail (4.5) - Glass (5.5) - Streak plate (6.5)

Facts:Facts:

MOH’S HARDNESS SCALE

Mohs hardness scale was developed in 1812 by Friedrick Mohs (an Austrian mineral expert) as a method to identify minerals.

This scale uses 10 minerals to represent variations in hardness.

FactsFacts

::

FACTS:

FACTS:

LUSTERRefers to the way light reflects from the surface of the mineral.

There are two types of luster, Metallic: looks like polished metal. Nonmetallic: does not look like polished metal. Nonmetallic can be shiny or dull.

PYRITE HAS METALLIC LUSTER

QUARTZ HAS NONMETALLIC LUSTER

STREAKThe streak of a mineral refers to the ("powder color") left on a streak plate after rubbing a mineral across its surface.

GOLDWhen gold is run across a streak plate it makes a yellowish-gold color. That makes sense.

PYRITE OR “FOOL’S GOLD”When pyrite is run across a streak plate, it has a black or dark green streak.

Pyrite is not worth much money, while gold is worth a lot. They look alike, so miners call it fool’s gold.

HEMATITEHematite’s color is grey, but its streak is red. Hema means blood. The mineral was named hematite because it looked like it was bleeding when it was taken across a streak plate.

ONE MINERAL PROPERTY WE WILL NOT USE…

COLOR S

EE WHY

ON THE N

EXT

SLIDE

A MINERAL CAN BE MANY DIFFERENT COLORS. BELOW IS MICA.

MANY MINERALS CAN BE THE SAME COLOR. BELOW ARE GOLD COLORED MINERALS. WHICH ONE IS GOLD?

THE

ANSWER

…NONE O

F TH

EM WERE R

EAL GOLD

.

JUST

LIKE W

ITH P

EOPLE…

OUTSID

E COLO

R DOES N

OT TE

LL YO

U MUCH

ABOUT TH

E IMPO

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CHARACTE

RISTI

CS.

COLOR Most obvious, but often misleading

way to identify a mineral thus it is the least useful because many minerals have similar color.

Different colors may result from impurities or they can change colors in various circumstances. This is because small amounts of different elements can give the same mineral different colors.

CLEAVAGENot all minerals have cleavage.

Some minerals split easily along a flat surface. It’s the way some minerals break along certain lines of weakness in their structure.

Cleavages are described in terms of their quality - how smoothly the mineral breaks - and their difficulty - how easy, or how hard, it is to produce the cleavage.

The number of lines that are created when a mineral is split will be the number of cleavage lines.

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.

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

If you have tim

e

If you have tim

e

try the other lin

ks.

try the other links.

Go back to ikeepbookmarks

Go back to ikeepbookmarks

MINERALS and try the other lin

ks

MINERALS and try the other lin

ks