Minerals Flashcards
(24 cards)
Minerals are the building blocks of what?
Rocks
What are the 5 characteristics of minerals?
- Naturally occuring
- Solid substance
- Orderly crystalline struture
- Definite chemical composition
- Generally considered inorganic
What are the 4 main ways minerals form?
- Crystallization from magma
- Precipitation
- Pressure and temperature
- Hydrothermal solutions (between 100 degrees C and 300 degrees C)
How are the physical properties of minerals determined?
Determined by the internal arrangment of the atoms
What are minerals that have different structural forms of a single chemical element called?
Allotropes
How do minerals differ from each other?
They are grouped according to their chemical composition
Describe silicates (4 descriptions)
- Most common group of minerals on earth
- Consists of the two most abundant element’s in Earth’s crust: Silicon and Oxygen
- Silicon and Oxygen combine to form a structure called the silicon-oxygen tetrahedron. Consists of one silicon atom and four oxygen atoms
- Quartz is the most common silicate mineral. Feldspar is also common
Describe Carbonates (6 descriptions)
- 2nd most common mineral group
- Contains the elements carbon, oxygen, and one or more other metallic elements. Formula will contain CO3
- Calcite (CaCO3) is the most common carbonate mineral
- Dolomite (CaMg(CO3)2) is another common carbonate mineral
- Both limestone and marble are rocks composed of carbonate minerals
- Acid will react with carbonates
Describe Oxides (4 descriptions)
- Contain oxygen and one or more other elements, which are usually metals
- Hematite (Fe2O3) and magnetite (Fe3O4) are common oxides
- Rutlie (TiO2) is titanium oxide and is formed as magma cools deep beneath Earth’s surface
- Corundum (AlO3) forms when existing minerals are subjected to changes in temperature and pressure. Red rubies and blue sapphires are popular corundum gemstones
Describe Sulfates (3 descriptions)
- Contains SO4 (sulfer and oxygen)
- Sulfates form when mineral-rich waters evaporate
- Examples include anhydrite (CaSO4) and gypsum (CaSO4 * 2H2O)
Describe Sulfides (3 descriptions)
- Contain sulfer and generally one metal
- Often form from thermal, or hot-water, solutions
- Galena (PbS), sphalerite (ZnS), and pyrite (FeS2) are common sulfides
Describe Halides (4 descriptions)
- Contain a halogen ion plus one or more other elements
- Include flourine (F), chlorine (C), bromine (Br), and iodine (I) (elements in group 17 on the periodic table)
- Halite (NaCl), or table salt, is a common halide
- Flourite (CaF2) forms when salt water evaporates
Describe Native Elements
- Group of minerals that exsist in relatively pure form
- Gold (Au), silver (Ag), copper (Cu), sulfer (S), and carbon (C) are common native elements
- Native forms of carbon are diamond and graphite
What are the 7 main ways to identify a mineral?
- Color
- Streak
- Luster (metallic or nonmetallic)
- Hardness (uses Moh’s Hardness Scale)
- Breakage pattern (cleavage: pattern/smooth and Fracture: random)
- Acid tests (carbonates (like calcite and dolomite) will bubble)
- Density or Specific Density (ratio to the density of water)
What are some distinctive properties of minerals? (7)
- Feel
- Magnetic
- Double refraction
- Smell
- Taste
- Flame color
- Fluorescence
What are some distinctive points on the Moh’s Hardness Scale?
2.5 - Fingernail
3 - Copper penny
5.5 - Glass
6.5 - Steel file
What are the major rock-forming minerals? (4)
Quartz, feldspar, calcite, and mica
What is an ore?
Ore is a useful metal or valuable mineral that can be mined at a profit. Common ore minerals are: pyrite, magnetite, hematite, galena, graphite, and sulfer
What are the major elements found in earth’s crust?
Oxygen, silicon, aluminum, and iron
Why are the certain common metallic elements (iron, aluminum, silicon) rarely, if ever, found in the native state?
These elements are highly reactive and form compounds with other elements
Cleavage is cause by the strength of the ______________ within the mineral’s crystal structure
Bonds between atoms
Who devised the hardness scale?
Friedrich Mohs
What mineral is magnetic?
Magetite (or lodestone)
What mineral has double refraction?
Calcite
