ESCI REVIEWER Properties of Minerals and Mineral Groups

review

Earth Materials

refer to substances or objects extensively used in geological and biological processes on the surface of the planet.

Earth Material

Minerals, Rocks, Energy Sources, Soil and Water

Mineral

It is a naturally occurring, inorganic, homogeneous solid, with a definite chemical composition, and an ordered crystalline structure.

Characteristics of Minerals

• Homogenous

• Naturally formed

• Inorganic Substance

• Solid

• Definable Chemical Composition

• Crystalline Structure

Solidification

Freezing

Precipitation

dissolved in the water bond and separate out of the water

Solid-State Diffusion

movements through a solid and resulting to crystal lattice.

Biomineralization

animals produces minerals

Fumarolic Mineralization

precipitation directly from gases

Physical Properties of Minerals

• Color

• Streak

• Luster

• Crystal habit

Color

refers to certain wavelengths of light that are reflected by a mineral and is perceived by the observer

Streak

is the color of the powdered form of a mineral.

Luster

is the appearance of the mineral surface and is dependent on how it reflects light

Crystal habit

is the characteristic shape in which a mineral grows and is a projection of the mineral’s crystal structure.

Allochromatic minerals

color is not a reliable diagnostic property since small impurities may dramatically alter their color.

idiochromatic minerals

are strongly colored which drowns out any impurities in color.

Pseudochromatic minerals

Are false-colored minerals. Their colors are due to light diffraction.

Physical Properties of Minerals 2

• Cleavage

• Fracture

• Hardness

• Specific Gravity

Cleavage

is the tendency of some minerals to break along flat surfaces.

Fracture

is the pattern in which the mineral breaks aside from its planes of cleavage.

Hardness

is the resistance of the minerals to scratching.

Specific Gravity

is the ratio of a minerals’ weight to the weight of an equal volume of water.

Mohs Scale of Hardness

1. talc

2. gypsum

3. calcite

4. flurite

5. apatite

6. feldspar

7. quartz

8. topaz

9. corundum

10. diamond

Ionsdaleite

58% harder than diamond.

Solubility

refers the ability of a substance to dissolve in a solvent at a specified temperature.

Melting point

refers to the temperature at which solid turns into liquid.

Elements

Most of the minerals here are composed of only one element. Having knowledge about elements enables scientists to identify bonding possibilities and compounds that can be created.

Elements Example Minerals

copper, gold, silver, sulfur.

Sulfides

Minerals under these group are composed of a metal joined by a sulfur. Metallic luster is the characteristic that distinguish them.

Sulfides Example Materials

cinnabar(HgS), pyrite(FeS2)

Halides

These are nonmetal groups which consists of chlorine, fluorine, bromine, and iodine as their main chemical constituent.

Halides Example Materials

fluorite(CaF2), halite(NaCl), diabolite

Oxides and hydroxides

These are mineral groups composed of one or more metals joined with oxygen, water, or hydroxyl (OH)

Oxides and hydroxides Example Materials

cuprite(Cu2O),hematite(Fe2O3)

Nitrates, carbonates, borates

It is formed when a metal is combined with carbon, nitrogen and boron.

Nitrates, carbonates, borates Example Materials

malachite,nitratine, borax

Sulfates

One or more metal is combined with a sulfate compound (SO4)

Sulfates Example Materials

anhydrite (CaSO4)

Chromates, molybdate, tungstates

substituted the place of the sulfate group. These minerals are usually brightly colored, brittle and dense.

Chromates, molybdate, tungstates Example Materials

wulfenite(PbMoO4), scheelite(CaWO4)

Phosphates, arsenates, vanadates

One or metal is chemically combined with the Phosphates, arsenates, vanadates group.

Phosphates, arsenates, vanadates Example Materials

apatite, lazulite,vanadinite

Silicates

This is the largest mineral group. Minerals under this group have different amounts of silicon and oxygen

Silicates Example Materials

dioptase,labradorite