Final Exam study Flashcards
What is a mineral?
Minerals are the building blocks of rocks. They are non-living, solid, and, like all matter, are made of atoms of elements. Minerals are typically formed when molten rock, or magma, cools, or by separating out of mineral-rich water, such as that in underground caverns.
What is the largest group of minerals?
silicates
What is the hardest naturally occurring mineral?
diamonds
What is the softest naturally occurring material?
talc
What is the formula for calculating DENSITY?
Mass / Volume = Density
Explain the Moh scale of hardness - what is it, what is it used for, and what is the ranking.
Mohs hardness refers to a material’s ability to resist abrasion or scratching. The Moh scale of hardness is used to rank gemstones and minerals according to hardness, on a scale from 1 (very soft) to 10 (very hard).
Name 4 physical properties
Color, streak, luster, hardness
What is luster?
Luster is a characteristic of the light reflected by a mineral. Luster has two categories, metallic and nonmetallic .
What is streak?
The streak of a mineral is the color it displays in finely powdered form.
What is hardness?
Hardness is how well a substance will resist scratching by another substance. /hardness.aspx#sthash.zHuvUChn.dpuf
What is crystal?
A crystal is a solid in which the particles are arranged in a pattern to make shapes with flat surfaces
What is magnetism?
A characteristic that allows a mineral to attract or repel other magnetic materials.
What is Specific Gravity?
Specific Gravity of a mineral is a comparison or ratio of the weight of the mineral to the weight of an equal amount of water.
What is fracture?
Breakage of a mineral, not along planes of weakness in the crystral structure.
What is a Gem?
A gem is a natural, mineral or organic substance, that has substantial beauty, rarity, and durability.
What is ore?
Rock or earth from which metal can be obtained
What is a rock?
A naturally occurring solid aggregate of one or more minerals.
How does an igneous rock form?
Igneous rock is formed when magma cools and solidifies, it may do this above or below the Earth’s surface.
Explain the Mafic igneous rock classification.
Mafic igneous rocks are dark colored and consist mainly of magnesium and iron.
Explain the Felsic igneous rock classification.
Felsic igneous rocks are light in color and are mostly made up of feldspars and silicates.
What is Ultramafic?
Ultramafic igneous rocks are very dark colored and contain higher amounts of magnesium and iron than mafic igneous rocks.
What is the difference between INTRUSIVE and EXTRUSIVE igneous rocks?
The difference between an Extrusive and Intrusive igneous rock is the way in which they cool. An Extrusive igneous rock cools very fast on the surface and is created by lava. Since the cooling process is very fast extrusive igneous rocks have very small crystals (fine grained). On the other hand an Intrusive igneous rock cools very slowly beneath the surface and is created by magma. Since the cooling process is very slow intrusive igneous rocks have very large crystals (coarse grained).
What are the 8 most abundant elements in earth’s crust (the ones which most rocks are made up of)?
Oxygen, Silicon, Aluminum, Iron, Calcium, Sodium, Potassium, Magnesium (O SIC SPAM)
What is sediment?
Solid fragments of inorganic or organic material that come from the weathering of rock and are carried and deposited by wind, water, or ice.
What is the difference between Clastic vs. Nonclastic sedimentary rocks?
Clastic rock is formed from particles of other rock (this is the most common sedimentary rock). Non-clastic is composed of chemical precipitate out of solution.
What are the three forms of sedimentary rocks?
Clastic (rocks are accumulations of little pieces of broken up rock which have piled up and been “lithified” by compaction and cementation). Chemical (formed when standing water evaporates, leaving dissolved minerals behind).
Organic (any accumulation of sedimentary debris caused by organic processes. Many animals use calcium for shells, bones, and teeth).
What are the three types of bedding?
Bedding (a series of visible layers
within a rock; most common
sedimentary structure).
Graded bedding (a progressive change in grain
size from bottom to top of a bed).
Cross-bedding (a series of thin, inclined
layers within a horizontal bed of rocks).
What is the difference between evaporites and precipitates?
Evaporites are water-soluble mineral sediments that result from concentration and crystallization by evaporation from an aqueous solution. Evaporites form in dry climates where the water can rapidly evaporate leaving sediment behind to precipitate.
Precipitates are minerals that settle or rain down after forming from saturated solutions containing the necessary ingredients for that mineral’s formation.
What are the two types of metamorphic rocks?
Foliated and non-foliated
Describe foliated metamorphic rocks.
Foliated metamorphic rocks are formed within the Earth’s interior under extremely high pressures that are unequal, occurring when the pressure is greater in one direction than in the others (directed pressure). This causes the minerals in the original rock to reorient themselves with the long and flat minerals aligning perpendicular to the greatest pressure direction. This reduces the overall pressure on the rock and gives it a stripped look.
Describe non-foliatted metamorphic rocks.
Nonfoliated metamorphic rocks are formed around igneous intrusions where the temperatures are high but the pressures are relatively low and equal in all directions (confining pressure). The original minerals within the rock recrystallize into larger sizes and the atoms become more tightly packed together, increasing the density of the rock.
What is Regional metamorphism?
Characteristics of regional metamorphism:
- Occurs over large areas (1000’s of sq. miles)
- Closely related to episodes of mountain building
- Both temperature and pressure important
What is Contact metamorphism?
Contact metamorphism is a type of metamorphism where rock minerals and texture are changed, mainly by heat, due to contact with magma. This is an easy name to recall if you remember that these rocks change by actually coming in contact with something very hot, like magma.
What two things are necessary for rocks to undergo metamorphism?
Heat and pressure!
Which type of rock (sedimentary, igneous or metamorphic) can become a metamorphic rock?
Sedimentary and igneous can become metamorphic. Metamorphic rocks are already metamorphic :)
How are metamorphic rocks formed?
Metamorphic rocks are made from the transformation of other sedimentary and/or igneous rocks through a process called metamorphism, “change in form”. The original rock is subjected to heat and pressure, causing physical and/or chemical change.
How are igneous rocks formed?
Igneous rock is formed through the cooling and solidification of magma or lava.
How are sedimentary rocks formed?
Sedimentary rocks are formed from pre-existing rocks or pieces of once-living organisms. They form from deposits that accumulate on the Earth’s surface. Sedimentary rocks often have distinctive layering or bedding.
What is the formula for pressure?
Pressure = Force / Area
or P = F / A
If a person weighs 54 kg (force) and the area of their hell (which is stepping on the ground) is 60cm2 (squared cm)…what is the amount of pressure being put on the person’s heel?
P = Force / Area... P = 54 kg / 60cm2 P = 0.9 kg/cm2
What kind of change, chemical or physical, do rocks undergo when they are HEATED?
CHEMICAL change
What is the process that leads to the formation of IGNEOUS rock?
Igneous rocks are called fire rocks and are formed either underground or above ground. Underground, they are formed when magma deep within the Earth becomes trapped in small pockets. As these pockets of magma cool slowly they become igneous rocks. Igneous rocks are also formed when volcanoes erupt. Igneous rocks are formed as the lava cools above ground. The upper 16 km of the Earth’s crust is composed of 95% igneous rock.
Read more: http://www.universetoday.com/82009/how-are-igneous-rocks-formed/#ixzz33sdTy5Gp
What is the process that leads to the formation of SEDIMENTARY rock?
Sedimentary rocks are formed by sediment that is deposited over time, usually as layers at the bottom of lakes and oceans. This sediment can include minerals, small pieces of plants and other organic matter. The sediment is compressed over a long period of time before consolidating into solid layers of rock. Sedimentary rocks forms layers called strata which can often be seen in exposed cliffs.
Sedimentary rocks cover the majority of the Earth’s rocky surface but only make up a small percentage of the Earth’s crust compared to metamorphic and igneous types of rocks.
What is the process that leads to the formation of metamorphic rock?
Metamorphic rocks have been changed over time by extreme pressure and heat. Metamorphic rocks can be formed by pressure deep under the Earth’s surface, from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates. Uplift and erosion help bring metamorphic rock to the Earth’s surface.
Explain the ROCK CYCLE.
The Rock Cycle is a group of changes. Igneous rock can change into sedimentary rock or into metamorphic rock. Sedimentary rock can change into metamorphic rock or into igneous rock. Metamorphic rock can change into igneous or sedimentary rock.
Explain the Theory of Plate Tectonics.
The Theory of Plate Tectonics states that earth’s surface (outer crust) is broken into shifting plates that move relative to one another. The theory explains the how and why behind mountains, volcanoes, and earthquakes, as well as how, long ago, similar animals could have lived at the same time on what are now widely separated continents.
Explain the Continental Drift Theory.
Once all the continents were joined in a super-continent, called Pangaea. Over a vast period of time, the continents drifted apart to their current locations.
What causes plate tectonic movement?
Mantle convection, gravity and the Earth’s rotation cause the plates to move. Plates at the surface move because of the intense heat in the Earth’s core that causes molten rock in the mantle layer to move. It moves in a pattern called a convection cell that forms when warm material rises, cools, and eventually sink down. As the cooled material sinks down, it is warmed and rises again.
What evidence is used to support seafloor spreading and continental drift theory?
The fit of the continents, glacial till deposits, and the shifting of climatic belts over time, paleomagnetism (when hot magma rises to the earth’s surface and cools, the minerals become magnetized in alignment with the Earth’s magnetic field), and mantle convection.