Optical and Physical Properties of Minerals

Discusses the different Optical and Physical properties of Minerals

1. MINERALS

2. How is a mineral different
from a rock?

3. MINERALS

4. Mineralsarethebuildingblocksofrocks.They
havebeenusedforbasicnecessitiesandfor
decorativepurposessinceprehistorictimes.These
mineralsthatarecommonandabundanton
Earth'scrustareknownasrock-formingminerals.
How is a mineral different from a rock?

5. 1.Naturally-occurring-Itisamineralifithasbeenformedby
geologicprocesseswithoutanyhumanintervention.
2.Inorganic-Amineralisinorganicifitisformedbyinorganic
processesanddoesnotcontainanyorganiccompounds.
However,mineralslikecalciteandothershell-forming
materialsareformedthroughorganicprocessesbutarestill
consideredasmineralsiftheybecomepartofarock.
To determine if an Earth mineral is a mineral,
it should exhibit the following characteristics:

6. 3.Solid-Amineralshouldexhibitstabilityatroom
temperature,whichcanonlybeattainedifitissolid.
4.Definiteinternalstructure-Mineralslooklikecrystalssince
thearrangementoftheiratomsisorderedandrepetitive.
Thus,naturally-occurring,inorganicsolids,suchasobsidian
volcanicglass,cannotbeconsideredamineralsincetheylack
acrystallinestructure.
To determine if an Earth mineral is a mineral,
it should exhibit the following characteristics:

7. 5.Definitechemicalcomposition-Mostmineralsare
chemicalcompoundsandcanthereforeberepresented
usingafixedorvariablechemicalformula.Anexampleof
amineralwithafixedchemicalformulaisquartz(SiO2).
Thisindicatesthatthemineralquartzcontainsonesilicon
atomandtwooxygenatoms.
To determine if an Earth mineral is a mineral,
it should exhibit the following characteristics:

8. Is Ice considered a mineral?

9. Optical
Properties

10. Luster
A mineral's luster is the overall
sheen of its surface –it may
have the sheen of polished
metal, or that of an unpolished
metal that is pitted by
weathering –or it may have
the sheen of glass, or look dull
or earthy, etc.

11. Look like metal
and are shiny
Metallic
Glassy, Earthy, Pearly, or
Greasy
NonMetallicSubMetallic
Develop a dull coating
and are not as shiny
Lusters

12. Metallic
Ex. Gold
NonMetallic
Ex. Quartz
SubMetallic
Ex. Pyrite
Lusters

13. a mineral’s ability to
transmit light
determines whether:

14. •Transparent objects
allowlightto pass
through them.
•Translucent objects
come in between
opaque and transparent
materials.
•Opaqueobjectsblock
lightanddonotallowit
totravelthroughthem.

15. Color –It is the property
of a mineral that is
easiest to identify.

17. Streakis simply the color of a mineral
powder. Many minerals have a
different color when powdered than
they do in crystal or massive forms.

18. Habitis the general appearance
amineraltends to have –whether it is
found as blocky crystals, long slender
ones, or aggregates of some type, etc.

20. a mineral’s ability to
transmit light
determines whether:

21. It is a measure of a
mineral’s resistance to
abrasion or scratching.
Hardness

22. It is the tendency of a mineral
to break along planes of
weakness.
Cleavage

23. It is exhibited if the mineral
does not have a cleavage
plane.
Fracture