Review#4 minerals

L.O: REVIEW MINERALS & ROCKS

MINERALS ARE NATURALLY OCURRING, INORGANIC SOLIDS.

EARTH’S ROCKS ARE MADE MINERALS

THERE ARE OVER 2000 MINERALS, BUT A DOZEN ARE COMMON.

Hard rocks are made of hard minerals. Softer rocks of soft minerals

Which rock strata is made of the hardest (most resistant to weathering) minerals? How do you know?

Which rock strata is made of the softest (least resistant to weathering) minerals? How do you know?

Most minerals are made of the same elements: especially oxygen & silicon

THE DOZEN COMMON MINERALS ARE CALLED: THE ROCK FORMERS.

BECAUSE MOST OF EARTH’S ROCKS ARE MADE FROM THEM.

MINERALS GET THEIR PHYSICAL PROPERTIES FROM THE INTERNAL ATOMIC (CRYSTALLINE)

ARRANGEMENT OF THEIR ATOMS.

EX: DIAMONDS AND GRAPHITE ARE PURE CARBON ATOMS, BUT HAVE VERY DIFFERENT PROPERTIES BECAUSE THEIR

CARBON ATOMS ARE ARRANGED DIFFERNTLY.

MANY, MANY, MANY MINERALS ARE USEFULL TO HUMANS BECAUSE OF THEIR UNIQUE

PHYSICAL PROPERTIES.

SEE PAGE 15 OF YOUR EARTH SCIE CE REFERENCE TABLE.

SCIENTISTS IDENTIFY MINERALS THROUGH THEIR PHYSICAL AND CHEMICAL PROPERTIES.

• COLOR• HARDNESS• STREAK• LUSTER• CLEAVAGE• SPECIAL PROPERTIES.

On the regents, I will use cleavage/fracture, luster, streak and hardness to identify one mineral.

COLOR

• Some minerals can be identified by their color ex: sulfur is always yellow.

• Color is NOT very useful because some minerals come in different colors. Ex: quartz comes in 7 colors

• Sometimes very different minerals have the same color. Gold and pyrite are bright yellow.

Hardness: the ability of a mineral to resist being scratched.

Hard minerals scratch soft minerals.

On the regents I will scratch my mineral on a glass plate….

If my mineral is harder than glass, it will scratch the glass plate….

If my mineral is softer than glass, it won’t scratch the glass plate….

Moh’s scale lists the hardness of some minerals

Moh’s scale is used to determine the hardness of unknown minerals

Streak: is the powder residue when a mineral is rubbed on a bathroom tile

A mineral’s Streak is like a “finger print”. Its streak is always the SAME color.

On the regents I will see if my mineral leaves a colored streak or non-colored (white ) streak

Cleavage and fracture: how mineral breaks into pieces.

Cleavage: minerals breaks into smooth or flat pieces

fracture: minerals breaks into uneven pieces

On the regents, I will see if my mineral shows cleavage or fracture.

Luster: the shininess of the mineral. If the mineral shines like metal, glass or dull (no

shine).

Metallic luster: shines like metal

non-metallic (glassy) luster: looks like glass

Dull luster: does not shine.

On the regents, I will see if my mineral has a metallic luster or non-metallic luster.

Special properties

• The mineral sulfur has a rotten egg smell.• Biotite mica looks like plastic.• Halite tastes salty• Calcium carbonate fizzes with acid.

I will use page 15 of the ESRT to identify minerals.

Turn to page 191 of your green workbook