NATSCI4_Minerals

• Minerals are

  1. Naturally occurring
  2. Inorganic
  3. Homogeneous Solid
  4. Definite chemical composition
  5. Solid-ordered internal structure
• Mineraloid is

  1. Naturally occurring
  2. Inorganic
  3. Amorphous
  4. Does not exhibit crystallinity
• The properties of a mineral are

  1. Crystal Habit/Form
  2. Luster
  3. Color
  4. Streak
  5. Hardness
  6. Cleavage
• A crystal habit is the external expression of a mineral’s internal orderly arrangement of atoms
• A crystal habit is the shapes and aggregates that a certain mineral is likely to form
• Luster is the ability of minerals to reflect light.
• The luster of a mineral can be metallic or non-metallic
• Color is caused by the absorption or lack of absorption of various wavelengths of light
• Color may also be due to impurities so it is not a good diagnostic property.
• Streak is the color of a mineral in powdered form
• Metals usually have a dark streak
• Hardness is the resistance of minerals to abrasion or scratching
• Most common hardness scale is Mohs Hardness Scale
• The hardness scale number of Talc is 1
• The hardness scale number of Gypsum is 2
• The hardness scale number of a fingernail is 2.5
• The hardness scale number of Calcite is 3
• The hardness scale number of a copper coin is 3.5
• The hardness scale number of Fluorite is 4
• The hardness scale number of Apatite is 5
• The hardness scale number of a knife or glass is 5.5
• The hardness scale number of Feldspar is 6
• The hardness scale number of steel is 6.5
• The hardness scale number of Quartz is 7
• The hardness scale number of Topaz is 8
• The hardness scale number of Corundum is 9
• The hardness scale number of Diamond is 10
• Cleavage is the tendency of a mineral to break in particular directions due to zones of weakness in the crystal structure
• Fractures or irregular breakages occur when bond strengths in a crystal structure are equal in all directions
• The most abundant common element in the Earth's crust is Oxygen with 47%.
• The second most abundant common element in the Earth's crust is Silicon with 28%.
• Feldspar and quartz are the two most common silicate minerals
• Calcite (CaCO3) is the most common carbonate mineral
• Pyrite, or iron sulfide, is a common sulfide mineral known as fool’s gold.
• The most abundant mineral in the Earth's crust is Plagioclase feldspars with 39%
• The second most abundant mineral in the Earth's crust is Potassium feldspars with 12%
• Common rock-forming minerals include quartz, feldspar, mica, amphibole, pyroxene, olivine, calcite, clay, carbonates, and hematite.
• Minerals that are of economic importance are Ore and Gemstones
• Ore are useful metallic (and some nonmetallic) minerals that can be extracted and which contain useful substances
• Gemstones are minerals that are highly prized for beauty, durability, and rarity