minerals

• Resource


  Stock or supply of anything that can be drawn on by anyone to function effectively
• Mineral


  A solid, inorganic substance of natural occurrence, building blocks of rocks

  
• Rock


  A conglomerate of various minerals formed on Earth's surface

  
• Characteristics of a Mineral

  • Naturally Occurring
  • Inorganic/Abiogenic
  • Stable/Solid
  • Definite Chemical Composition
  • Ordered Internal Structure

  
• Naturally Occurring


  Means that a substance is not man-made, exists by nature without artificial aid
• Inorganic/Abiogenic


  Synthesized through geological systems and processes, not made from living organisms
• Stable/Solid


  Must stay solid at room temperature (20-25°C), not in liquid or gas forms
• Definite Chemical Composition


  Must be defined by their chemical composition, expressed by their chemical formula in specific ratios
• Ordered Internal Structure


  Must have regular, repetitive geometric patterns or crystal structures
• Physical Properties of Minerals

  • Color
  • Streak
  • Luster
  • Penetrability/Diaphaneity
  • Tenacity
  • Hardness

  
• Color

  Physical color of mineral, considered unreliable as some exhibit many hues and many share similar colors
• Streak

  A mineral's color in powdered form, achieved by rubbing the mineral across an unweathered surface

  
• Types of Luster


  • Adamantine
  • Earthy/Dull
  • Greasy
  • Metallic
  • Pearly
  • Resinous
  • Silky
  • Submetallic
  • Vitreous
  • Waxy
• Penetrability/Diaphaneity


  Property of minerals to allow light to pass through, can be transparent, translucent or opaque
• Tenacity


  Mineral's resistance to breaking or deforming
• Hardness


  Measure of a mineral's resistance to abrasions or scratches

  
• Mineral Splitting


  • Cleavage
  • Fracture
• Cleavage


  Tendency of minerals to break along planes of weakness (smooth, flat surfaces)

  
• Cleavage Habits


  • Basal/Pinacoidal
  • Prismatic
  • Cubic
  • Rhombohedral
  • Octahedral
  • Dodecahedral
• Basal/Pinacoidal Cleavage


  Cleaves at the base, one direction
• Prismatic Cleavage


  Cleaves to form prisms, two directions
• Cubic Cleavage


  Cleaves as cubes, three directions at right angles
• Rhombohedral Cleavage


  Cleaves into rhombohedrons, three directions not at right angles
• Octahedral Cleavage


  Cleaves as octahedrons, four directions
• Dodecahedral Cleavage


  Cleaves as dodecahedrons, six directions
• Fracture Habits


  • Conchoidal
  • Uneven
  • Hackly
  • Splintery
  • Earthy
  • Smooth
  • Subconchoidal
• Conchoidal Fracture

  Fracture resembles a semicircular shell with a smooth, curved surface

  
• Uneven Fracture


  Fracture leaves a rough or irregular surface

  
• Hackly Fracture


  Fracture resembles a broken metal, with rough, jagged points
• Splintery Fracture

  Fracture forms elongated splinters, exhibited by fibrous minerals
• Earthy Fracture

  Crumbly fracture, mineral crumbles upon fracture, reminiscent of dry earth

  
• Smooth Fracture


  Even fractures with a smooth surface reminiscent of a perfect cleavage
• Subconchoidal Fracture


  Cross between a conchoidal and smooth fractures, with a smooth, yet irregular rounded corners
• Parting


  Type of breaking that is often quite similar to cleavage, breakage along planes of weakness but in twinning planes
• Specific Gravity


  Ratio of the density of the mineral and density of water, < 1 means lighter than water and will float, > 1 means heavier than water and will sink
• Crystal Habits


  • Acicular
  • Banded
  • Bladed
  • Botryoidal
  • Columnar
  • Cubic
  • Dendritic
  • Dodecahedral
  • Drusy
  • Fibrous
  • Foliated
  • Geodic
  • Granular
  • Massive
  • Nodular
  • Octahedral
  • Oolitic
  • Pisolitic
  • Prismatic
  • Radiating
  • Rosette
  • Stalactitic
  • Striated
  • Tabular

  
• Acicular Crystals


  Have a needle-like shape
• Banded Crystals


  Have narrow layers (bands) of different color and/or texture

  
• Bladed Crystals

  Elongated crystals whose length exceeds mineral's thickness
• Botryoidal Crystals


  "A bunch of grapes" aggregates that are round