Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
45 Cards in this Set
- Front
- Back
|
Minerals?
|
Considered part of the human diet as vitamins or precious gems.
|
|
|
Rock?
|
"Conglomerate of minerals" Minerals are the building blocks of rocks.
Minerals are a mixture and each retains its color, luster, and physical properties. |
|
|
Some Rocks...
|
Are made up of more than one mineral. Granite is made of hornblende, quartz, and feldspars.
Some are only made of one mineral. Calcite makes up limestone. |
|
|
For a material to be considered a mineral...
|
It must color naturally, be inorganic, be solid, and have a definite chemical structure. Cubic zirconium is manmade, not a mineral. Nor are oils or gases, because they are not solid.
|
|
|
Unstable Elements
|
Most are unstable, therefore most minerals are made up of more than one element in order to gain stability.
|
|
|
Understanding Minerals?
|
To understand them we need to understand atoms. PS why do i have this flashcard?
|
|
|
Atoms?
|
Smallest particles of matter that have all the characteristics of an element.
|
|
|
Nucleus
|
Central region of an atom. Has protons with positive electronical charges and neutrons with no electrical charges.
|
|
|
Orbiting the Nucleus
|
are electrons with negative charges.
|
|
|
Energy Levels
|
Since each electron is located at a given distance from the nucleus, they create layers of "energy levels".
|
|
|
Atomic Number?
|
Number of protons in a nucleus.
|
|
|
Mass Number?
|
Total of protons and neutrons.
|
|
|
4000 Minerals?
|
Are already identified and each has a definite chemical structure and composition. Each mineral is made up of an element or elements. There are 112 known elements.
|
|
|
Free Atom?
|
Not combined with any other atoms. Has the same number of electrons as protons. The atomic number of a free atom equals the number of electrons.
C atom has 6 electrons to match 6 protons. Electrically neutral. |
|
|
Element?
|
Large collection of electrically charged neutral atoms all having the same atomic number.
|
|
|
Compound?
|
Combinations of 2 or more elements that are bonded together. When the bond is broken, the compound no longer exists.
|
|
|
Ions?
|
Atoms that have an electrical charge because of a gain or loss of electrons.
Na and Cl bond and make salt. Na loses one electron and becomes positively charged. Cl gains one and becomes negatively charged. Acts as an electrical glue. |
|
|
Isotopes?
|
Atoms of same element always have the same number of protons but commonly have a different number of neutrons. Element can have more than one mass number. Variations of that same element are the isotopes of the element.
|
|
|
Radioactive Decay?
|
Most of the nuclei of atoms are stable, some are not. Isotopes disintegrate and radiate energy and particles.
This happens because the chemical bonding between the atoms are not strong enough to keep them together. |
|
|
Disintegration Rate?
|
In unsteady nuclei it is steady and measureable. This makes some of the isotopes useful "clocks" for dating the events of Earth History.
|
|
|
8 Properties of Minerals?
|
Crystal Form
Luster Color Streak Hardness Cleavage Fracture Specific Gravity |
|
|
Crystal Form?
|
External look of a mineral that is caused by the internal arrangement of atoms. When a mineral forms without space restrictions, and has enough time to grow, it will usually develop well-formed crystal faces.
|
|
|
Luster?
|
Metallic and nonmetallic.
Quality of light reflected from the surface of the mineral. |
|
|
Metallic Luster?
|
Appearance of a metal (pyrite)
|
|
|
Nonmetallic Luster?
|
Other than metallic look:
Vitreous/gassy (Quartz) Pearly Silky Resinous and or Earthy/Dull |
|
|
Color?
|
Easy to recognize but not as reliable because impurities in minerals can cause color differences.
|
|
|
Streak?
|
Color of the mineral in its powdered form. This is obtained by rubbing the mineral against the porcelain streak plate.
Metallic minerals leave dense, dark streaks as opposed to nonmetallic minerals. |
|
|
Hardness?
|
Measure of the resistance of a mineral to abrasion.
Geologists use "Mohs Scale" to determine the hardness. |
|
|
Mohs Scale?
|
From 1-10 (hardest to softest)
1)Diamond (hardest) 2)Corundum 3)Topaz 4)Quartz 5)Feldspar 6)Apatite 7)Fluorite 8)Calcite 9)Gypsum 10)Talk (softest) |
|
|
Cleavage?
|
Tendency of a mineral to break among planes of weak bonding. Can be seen in micas. Mica has only one weak bond of direction. Fluorite has 8 directions while calcite has 3 and meets one another at 75 degree angles.
|
|
|
Fracture?
|
Minerals that do not cleave when broken will fracture. The fracture can be smooth curved surfaces (conchoidal) or fibers like abestos.
|
|
|
Specific Gravity?
|
Compares the weight of a mineral to the weight of an equal volume of water.
Cubic centimeter of a mineral weighs 3 times as much as a cubic centimeter of water- its specific gravity is 3. |
|
|
Mineral Groups?
|
4000 known but 12 are abundant and make up most rocks. Classified as "rock forming minerals."
Surprisingly, 8 of these elements make up 98% of the continental crust. |
|
|
Silicon and Oxygen?
|
Among the 8 elements, silicon and oxygen consist of 75% of the earth's continental crust.
|
|
|
Most common mineral groups?
|
- Silicates (silicon and oxygen)
- Carbonates (carbon and oxygen and other elements) - Gypsum - Halites |
|
|
Silicates?
|
Some building blocks called silicon oxygen tetrahedron and it has 4 oxygen atoms and 1 smaller silicon atom.
|
|
|
Tetrahedral Structures?
|
Can be connected by iron, magnesium, potassuium, Sodium, Calcium, etc.
|
|
|
Mikas?
|
In some mineral groups, since the silicon oxygen bonds are strong, the silicate minerals tend to cleave between the silicon oxygen structures rather than across them.
|
|
|
Quartz?
|
SiO2
Silicon-Oxygen bonds are strong in every direction- no cleavage, only fractures. |
|
|
Some Silicate minerals?
|
Some crystalize from magma at or near the Earth's surface (low temp/low pressure) or at greater depths (high temp/high pressure)
Chemical composition of magma and the depth (temp/pressure) determine which mineral will be produced. Olvine crystalizes at 12000C. Quartz at 7000C. |
|
|
Nonsilicate Minerals?
|
Make up about 25% of the continental crust. Major group is the "carbonates" calcite (CaC03)
|
|
|
Calcite Minerals
|
Come together and make up the rock called limestone.
|
|
|
Evaporites?
|
Halites and Gypsum- ancient seas dry up and leave thick salt layers behind.
|
|
|
Other Mineral Groups?
|
Oxides/sulfides/sulfates and native elements that have economic values.
|
|
|
Mineral Resources?
|
Can be recovered for use. Reserves can be extracted profitably. ORE= Useful metallic minerals that can be mined at a profit.
Economic changes affect Ore values. |
