WednesdayJanuary 16, 2013(Physical Properties of

Minerals – Streak, Hardness, and Cleavage; Begin Studying Mineral

Samples)

The Launch PadWednesday, 1/16/13

The pictures illustrate three

types of ______, which is

a _________.

quartzmineral

AnnouncementsHappy Appreciate a Dragon

Day!

AnnouncementsI will be available after

school today until 5:00.

Assignment Currently Open

Summative or

Formative?Date Issued Date Due Date Into

GradeSpeed Final Day

Quiz 14 S4 12/12 12/12 12/19 1/16

Lab – Fossils F2 1/9 1/10 1/18

Quiz 15 S5 12/11 12/11 1/15 1/29

Video WS – Geologist's Notebook – What

Exactly Are Minerals?F3 1/14 1/18 1/18

Recent Events in ScienceNeon Lights Up Exploding Stars

Read All About It!www.sciencedaily.com/releases/201

3/01/130115085527.htm

An international team of nuclear astrophysicists has shed new light on the explosive stellar events known as

novae.These dramatic explosions are driven

by nuclear processes and make previously unseen stars visible for a

short time. The team of scientists measured the nuclear structure of the radioactive neon produced through

this process in unprecedented detail.Their findings, reported in the journal Physical Review Letters, show there is much less uncertainty in how quickly one of the key nuclear reactions will

occur as well as in the final abundance of radioactive isotopes than has

previously been suggested.

MineralsThe Building Blocks

of Rocks

Minerals - The Building Blocks of Rocks o Recall from chemistry that elements

and compounds are collectively known as “substances.”

o Elements bond together to form “compounds.”

o Elements and compounds have a definite chemical formula.o ex.) Elements: Na is sodium and Cl is

chlorine.o ex.) Compound: NaCl is sodium

chloride, or common table salt.o In geology, we normally call rocky

elements and compounds “minerals.”o Sodium chloride is called rock salt, or

halite, when we’re discussing minerals.

Figure 2.2

Minerals - The Building Blocks of Rocks A mineral is a naturally

occurring, solid chemical substance that has a

characteristic chemical composition that can be expressed by chemical

symbols and formulas.By comparison, a rock, which we will study later, is a mixture of minerals and does not have a specific

chemical composition.

Minerals range in composition from pure elements and simple salts to very

complex silicates with thousands of known forms.

The study of minerals is called mineralogy.

Figure 2.3

Minerals - The Building Blocks of Rocks A mineral is naturally

occurring, inorganic, solid in phase, possesses an

orderly internal structure of atoms, and has a

definite chemical composition.

Fluorite

CalciteQuartz

Minerals - The Building Blocks of Rocks Physical properties

of minerals Streak

When you rub a mineral on a flat surface, the color of the powder left behind on the

streak plate is the mineral's streak.

The streak and color of some minerals are the same. For others, the streak may be

quite different from the color.

Although the color of a mineral may not be very helpful in identification, the streak, which is the color of the

powered mineral, can be very useful.

Minerals - The Building Blocks of Rocks

Physical properties of minerals

HardnessMineral hardness is based on

the ability of one natural sample of matter to scratch

another.Diamond is the hardest

known naturally occurring substance, whereas talc is the

least hard.

Minerals - The Building Blocks of Rocks

Physical properties of minerals

HardnessThe hardness of a material is

measured against the Mohs scale by finding the hardest material that

the given material can scratch, and/or the softest material that can scratch the given material.

For example, if some material is scratched by apatite but not by

fluorite, its hardness on the Mohs scale would fall between 4 and 5.

Figure 2.13

Mohs Scale of Hardness

Minerals - The Building Blocks of Rocks

Physical properties of minerals

CleavageIn mineral terms, cleavage describes how a crystal breaks when subject to

stress on a particular plane.If part of a crystal breaks due to stress and the broken piece retains a smooth plane or crystal shape, the mineral has

cleavage.A mineral that never produces any

crystallized fragments when broken off due to stress has no cleavage.

Cleavage

Begin Studying Mineral Samples