Download Mineral Identification

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

History of geomagnetism wikipedia, lookup

Ferromagnetism wikipedia, lookup

Magnetotactic bacteria wikipedia, lookup

Magnetochemistry wikipedia, lookup

Crystal (comics) wikipedia, lookup

Transcript
The Oxides




These are more common minerals than sulfides
and metal oxides are prized because of their
economic value.
These minerals are the source of many metals we
use today. They are often found where metallic
ores have been oxidized or rusted.
These minerals must be refined to separate the
metal from the oxygen, however it is far easier
and far less polluting to refine oxides than
sulfides.
Oxides can be sub-metallic or non-metallic
lustre, have fairly high specific gravity (heavy)
and should be streaked if they are sub-metallic



Remember to streak all sub-metallic minerals
Have a magnet handy as the oxide Magnetite
is magnetic.
Remember to wash your hands after
handling, due to the presence of heavy
metals.
PROPERTY
Colour
3 very different possible forms:
• Red massive “common iron rust” coloured masses
• Deep red ,sub-metallic, hard botryoidal masses
• Silvery metallic blades with a reddish rust.
Crystal Form
Bladed metallic crystals, botryoidal masses
Cleavage/Fracture
rare
Lustre
Massive (earthy), botryoidal and metallic blades.
Hardness
Botryoidal and metallic form is surprisingly hard (6)
Specific Gravity
heavy
Streak
Always reddish-brown (rust coloured)
Other
It is a major ore of iron (used to make steel). You
can piles of at steel plants in Hamilton.
PROPERTY
Colour
Black
Crystal Form
Often massive, but it is commonly found in
octahedral crystals
Cleavage/Fracture
4 directions – hard to see
Lustre
Sub-metallic
Hardness
Very hard (7) – can scratch glass – unusual for a
sub-metallic mineral
Specific Gravity
Medium-heavy
Streak
black
Other
Magnetic
Another common iron ore.
Actual formula Fe2+Fe3+2O4 (spinel group)
Same crystal structure as chromite and can easily
be confused with chromite.
PROPERTY
Colour
Gun-metal grey
Crystal Form
Common (cubes, pyritohedrons, striated crystals)
but is usually seen massive
Cleavage/Fracture
Perfect in 3 directions 90˚ creating cubic
cleavage fragments
Lustre
Metallic – very lustrous cleavage faces
Hardness
Very Hard (9) – scratches glass
Specific Gravity
Very heavy due to the lead – densest mineral in
our set.
Streak
black
Other
Commonly associated with sphalerite.
Galena “rusts” to a duller grey
Non-magnetic
It is the main ore of lead in the world
PROPERTY
Colour
Yellow-gold – the colour is more yellow than
pyrite but less golden than gold.
Crystal Form
Almost always massive
Cleavage/Fracture
none
Lustre
Metallic
Hardness
hard (4.5) – cannot scratch glass – can be
scratched with a nail
Specific Gravity
Medium-heavy
Streak
black
Other
Non-magnetic
The problem is that it is often associated with
pyrrhotite which is magnetic
It is a major ore of copper. Used for wiring and
pipes.