lesson 4: rocks and minerals

• features

  1. geometric structure
  2. crystal habit
  3. physical properties
• mineral gems


  are rare and is used to make jewelry
• transparent


  allows some light to pass through it.
• muscovite


  example of tranparent
• translucent


  allows some of light to pass through it
• jadeite


  example of translucent
• opaque


  light cannot pass through
• hematite


  example of opaque
• luster


  amount of light reflects on a mineral's surface
• cleavage 


  smooth break
• fracture


  breaking in a random structure
• rock cycle

  1. lithification
  2. compaction
  3. cementation
• igneous rocks


  -from latin word ''ignis'' meaning fire

  -formed by volcanic activity

  -from magma
• extrusive


  -volcanic rock

  -forms small crystals
• intrusive


  -platonic rocks

  -forms big crystals
• lithification


  a process by which the sediments are transformed into solid sedimentary rocks
• compaction


  -piles of sediments accumulate

  -compacted by the weight of layers

  -ex: shale
• cementation


  -water containing cement materials seeps into the pores

  -fills open spaces & binds particles together

  -example; calcite
• detrital


  come from weathered rocks or made of small rock fragments
• chemical


  -come from soluble materials produced largely from chemical weathering
• metamorphic rocks


  come from pre-existing rocks called parent rocks
• metamorphism


  the process of transformation from parent rocks
• slate comes from shale
• gneiss comes from ganite
• marble comes from limestone