Properties of minerals

Crystal Structure A crystal is a solid in which the atoms are arranged in a pattern that repeats again and again..  Internal Arrangement of the Atoms A tetrahedral site lies in the ce

Properties of Minerals

What is a

mineral?

The Rules of the Mineral

 Every Mineral must follow these set of rules

Mineral Questions

1 Are pearls considered minerals?

• No, because they are made from

Crystal Structure

 A crystal is a solid in which the atoms are arranged in a pattern that repeats again and again

 Internal Arrangement of the Atoms

A tetrahedral site lies in the center of a 4-

A tetrahedral site lies in the center of a 4-

A tetrahedral site lies in the center of a 4-

A tetrahedral site lies in the center of a

A tetrahedral site lies in the center of a 4-

A tetrahedral site lies in the center of a 4-

A tetrahedral site lies in the center of a 4-

A tetrahedral site lies in the center of a 4-

A tetrahedral site lies in the center of a 4-

A tetrahedral site lies in the center of a 4-

A tetrahedral site lies in the center of a 4-

A tetrahedral site lies in the center of a 4-

Definite Chemical

Composition

 This means that a mineral always

contains certain elements in definite proportions

 Quartz- always has one atom of Silica for every two atoms of oxygen

The Mineral Beryl

Emerald Aquamarine

The Mineral Corundum

January - Garnet July - Ruby

February - Amethyst August - Peridot March -Aquamarine SeptemberSapphire April – Diamond October - Opal May – Emerald November - Topaz June - Pearl December - Zircon



Mohs Hardness Scale

 1 = Softest (talc or graphite)

 10 = Hardest (diamond)

 How do you determine if one mineral is harder than the other?

 Perform a scratch test

 If the mineral gets scratched it is softer

Which mineral is gold?

How would you be able to tell the difference?

Streak- the color of a mineral when it is made into a powder

 Pyrite(fool’s gold) is

very similar in color to

real gold, but Pyrite

has a greenish-black

streak and gold has a

gold streak.

Luster- describes how light

reflects off a minerals surface

 Metallic Luster- describes minerals that are shiny

 Glassy Luster- describes minerals that look like they have a glassy surface, ex Quartz

 *Minerals are usually described as

having a metallic or non-metallic luster.

Which mineral has a metallic luster and which has a glassy luster?

Crystal Shape

 Every crystal has a characteristic shape that is due

to its Crystal structure.

 Halite(NaCl or Salt)- will always have six sides and form a cube

Minerals will either break by

cleavage or fracture?

 Cleavage- a minerals ability to split

easily along flat surfaces

 Fracture- minerals which break with

rough or uneven surfaces

Special Properties

ultraviolet light ex.) Fluorite

naturally magnetic ex.) Magnetite

Calcite fizz when acid is placed on it

Fluorite

Scheelite(fluorescent mineral)

Magnetite