Properties of Minerals Earth’s Surface 2.2 (pg. 51-57) Ms. Wells, Science

Properties of Minerals: Why do we care? Property – characteristic, quality or trait of something Used to IDENTIFY a mineral Is it salt? Is it quartz? Is it talc? Who knows! TEST the properties to find out!

Property – characteristic, quality or trait of something

Used to IDENTIFY a mineral

Is it salt? Is it quartz? Is it talc? Who knows! TEST the properties to find out!

Properties of Minerals: Which are the most important? Streak Luster Cleavage or Fracture Density Hardness

Streak

Luster

Cleavage or Fracture

Density

Hardness

Appearance Property: Streak Streak – color of the powder a mineral leaves behind when you scrape it across something Shows true color better than looking at a whole mineral Use “streak plate” made of porcelain

Streak – color of the powder a mineral leaves behind when you scrape it across something

Shows true color better than looking at a whole mineral

Use “streak plate” made of porcelain

Appearance Properties: Luster Luster – the way a mineral reflects light (QUALITATIVE OBSERVATION  ) Luster Terms: Metallic – shiny like a metal Non metallic – not shiny like metal Oily – feels or looks greasy Glassy – shiny like glass Dull – plain, earthy

Luster – the way a mineral reflects light

(QUALITATIVE OBSERVATION  )

Luster Terms:

Metallic – shiny like a metal

Non metallic – not shiny like metal

Oily – feels or looks greasy

Glassy – shiny like glass

Dull – plain, earthy

Metallic Luster

Nonmetallic Luster

Breaking Properties: Cleavage or Fracture Cleavage – mineral breaks along a flat surface or into sheets Fracture – when a mineral breaks with lots of jagged edges

Cleavage – mineral breaks along a flat surface or into sheets

Fracture – when a mineral breaks with lots of jagged edges

Property: Density Density – mass divided by volume of a mineral (in other words: how heavy it is for how much space it takes up) GOLD is denser than PYRITE (“Fool’s Gold”) Feels heavier

Density – mass divided by volume of a mineral (in other words: how heavy it is for how much space it takes up)

GOLD is denser than PYRITE (“Fool’s Gold”)

Feels heavier

Fracture or Cleavage? Determined by the crystal structure of the mineral Crystal structure – how atoms of the mineral are arranged (special order of the atoms) ALL minerals have crystal structure, but there are different kinds

Determined by the crystal structure of the mineral

Crystal structure – how atoms of the mineral are arranged (special order of the atoms)

ALL minerals have crystal structure, but there are different kinds

Property: Hardness Hardness – a mineral’s resistance to being scratched test what can scratch it and what it can scratch Use “Moh’s Scale” to assign hardness Scale of 1 to 10 10 = hardest = diamond! 1 = softest = talc!

Hardness – a mineral’s resistance to being scratched

test what can scratch it and what it can scratch

Use “Moh’s Scale” to assign hardness

Scale of 1 to 10

10 = hardest = diamond!

1 = softest = talc!

Extra Special Properties 1. Fluorescence Fluorescent color under ultraviolet (UV) light 2. Magnetic Attract magnets 3. Acid reaction Carbon dioxide gas bubbles off when you drop acid on them Carbonates!

1. Fluorescence

Fluorescent color under ultraviolet (UV) light

2. Magnetic

Attract magnets

3. Acid reaction

Carbon dioxide gas bubbles off when you drop acid on them

Carbonates!

Fluorescence

Magnetic

Carbonate Acid Reaction

The End! YAY!