6B20 Identifying Rock Types

B20 Rock Type Background Ranger Ormond examined the hiker’s rock. Was it an igneous rock like kimberlite? Igneous, metamorphic and sedimentary rocks often look different from each other because they are formed differently. She wanted to compare the hiker’s rock to samples of metamorphic, sedimentary and igneous rocks. Can you help her figure out which rock is which?

B20 Rock Type Procedure On separate paper put Name, Hour, and Date. Make a 3-column data table with 9 rows and titles: Name, Observations, Rock Type (I,S,M) Use a magnifying lens to examine some rock samples and record observations in a table Check color, hardness, smoothness, streaks, & compare crystal sizes as small · or large • Compare the rocks to Vocab Rock Properties Are they Igneous, Sedimentary, or Metamorphic?

B20 Rock Type Data Table (copy) Rock Name Observations Type (I,S,M) Coal Gabbro Gneiss Granite Limestone Obsidian Phyllite Sandstone

B20 Rock Type Data Table: Obs Rock Name Observations Type (I,S,M) Coal Black layers, light, crumbly ? Gabbro Dark, shiny, large crystals ? Gneiss Color bands, small crystals ? Granite Large red crystals ? Limestone White/rose, soft, fossils ? Obsidian Black shiny, hard, smooth as glass ? Phyllite Gray bands, small crystals ? Sandstone Sand texture, crumbly ?

B20 Rock Type Analysis: Date________ Name______________________ Hr__ Copy and Explain each in 1 paragraph. Do all rocks of the same type look the same? What characteristic is most useful to identify each type of rock listed below? Explain. A. igneous B. sedimentary C. metamorphic 3. Which fact is most helpful in identifying an unknown rock and why? A) It is light gray, B) It is shiny, C) It was found high up on an extinct volcano, or D) It can easily fit in a kid’s hand.

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