rocks and minerals

minerals

are naturally occurring, inorganic solids with crystalline structure and chemical composition

• naturally occurring

• inorganic solid

• definite chemical composition

• ordered internal structure

general characteristics of a mineral

silicates

composed of primarily silicon-oxygen tetrahedrons (SiO4²) and are major rock-forming minerals

examples:

• olivine

• quartz

sulfides

consist of metal cations bonded to sulfide (S²-)

examples:

• galena

• pyrite

sulfates

consist of metal cation bonded to the SO4²- anionic group

example:

• gypsum

halides

composed of halogen ion, such as, chlorine or fluoride

examples:

• salt

• fluorite

carbonates

characterized by the presence of carbonic ion (CO3²-) which bonds element such as calcium or magnesium

examples:

• calcite

• dolomite

native metals

consist of single metal

• copper (Cu)

• gold (Au)

examples of native metals

color

is the most evident characteristic and is usually the first property used to identify minerals

streak

is the color of a material in its powdered form

streak plate

used to obtain a powdered form of a mineral by rubbing it on an abrasive ceramic tile

hardness

measurement of the strength of the chemical bonds in its structure

cleavage and fracture

the tendency of a mineral to break along planes of weakness

crystal form

is due to mineral’s define chemical composition

habit

is the outward appearance of the minerals crystal form

crystalline structure

is the crystal form of the mineral

transparency

indicates the extent of light that can pass through the minerals

magnetism

it indicates the ability of mineral to attract or repel other minerals

tenacity

the mineral's ability to hold its particles together or the mineral's level of resistance to stress such as bending, breaking, crushing, or tearing

luster

describes the appearance of light as it is reflected off its surface

odor

is a distinct smell of a mineral that is usually released from a chemical reaction manifested when the mineral is subjected to water, heat, air, or friction

density

a physical property where specific gravity is a measure

rocks

• are natural substances consisting of aggregate minerals clumped together with other earth materials glued by natural processes

• derived from the greek word “lithos” meaning “stone”

igneous rocks

are formed from the cooling and solidification of molten or partially molten volcanic material that came from within the earth like magma

“ignis” or “igneus”

came from a latin word which means “fire” or “fiery” where the name igneous rocks came from

• flooring

• table tops

example uses of igneous rocks

sedimentary rocks

• the products of the lithification of particles produced by the weathering of other pre-existing rocks

• formed from different material deposits on earth’s surface

• processes: (weathering & lithification) | (compaction & cementation) | (heat & pressure)

“sedentarious”

a latin word that means “sitting” where the name sedimentary rocks came from

• sandstones

• limestones

• shales

• construction materials (bricks & cement)

example uses of sedimentary rocks

metamorphic rocks

are rocks that are formed from igneous or sedimentary rocks that were exposed to high pressure, high temperature, or combination of both, deep below the surface of the earth

• “meta” meaning “change”

• “morph” meaning “form”

the word metamorphic rock comes was derived from the words

• building materials

• artwork

• decoration

example uses of metamorphic rocks

ore

is a rock that contains minerals with useful elements

surface mining

• allows extraction of ores that are close to earth’s surface

• involve removal and stripping of surface vegetation, dirt, and layers of bedrock to reach the mineral deposits

underground mining

• a mining technique used to dig tunnels or shalfs at greater depths to reach hard mineral deposits like ore that may contain gold, silver, and copper

• recover ores deeper into the earth's surface

extraction

the process of removing mineral resources from the earth's crust

drilling

to set charges for a blast

blasted ore

is hauled to the crusher

crushers / grinders

break up the ore to the size of small pebbles or sand

milling

is the process of separating the desired mineral from the unwanted rock called gangue

concentration and flotation

some minerals are separated by washing, flotation, or magnetic separation

smelting

uses high heat and chemicals to remove base metals and impurities from concentrates (above 1064 degrees celcius)

electrowinning

an electrical charge passes through causing copper ions to stick to the sheets