Name that Sedimentary Name that Sedimentary RockRock

Click the correct answers to Click the correct answers to learn your rock sample’s learn your rock sample’s

name.name.

Is it Coarse or Fine Grained?Is it Coarse or Fine Grained?

• The rock is made of distinct pieces The rock is made of distinct pieces of of rocks, sand, plants or shells.rocks, sand, plants or shells.

• The rock looks like it’s made of pieceThe rock looks like it’s made of pieces too small to see.s too small to see.

• The rock is made of mineral crystals The rock is made of mineral crystals that precipitated from water solution.that precipitated from water solution.

Coarse GrainedCoarse Grained

What are the pieces you see in your What are the pieces you see in your rock?rock?

• Pebbles and larger rock bitsPebbles and larger rock bits

• SandSand

• Plant fragmentsPlant fragments

• Shell fragmentsShell fragments

Pebbles or RocksPebbles or Rocks

Are the rock bits within your rock Are the rock bits within your rock sample rounded, or angular?sample rounded, or angular?

• Smooth and rounded.Smooth and rounded.

• Sharp and angular.Sharp and angular.

Fine GrainedFine GrainedWhat is your rock sample like?What is your rock sample like?

• Made of flat layers, dull and softMade of flat layers, dull and soft, with a reddish, , with a reddish, brown, grey, or blackish color.brown, grey, or blackish color.

• Light weight, black, dull and sooty to glassy luster, Light weight, black, dull and sooty to glassy luster, flammable.flammable.

• The rock fizzes in acidThe rock fizzes in acid, lighter in color, H = 3., lighter in color, H = 3.

• Glassy luster, hardness is seven, with a conchoidal Glassy luster, hardness is seven, with a conchoidal (“broken glass”) fracture.(“broken glass”) fracture.

Glassy Fine GrainedGlassy Fine Grained

What color is it?What color is it?

• Darker red, brown, grey, or black colDarker red, brown, grey, or black color.or.

• Lighter in color: white, tan, or light brLighter in color: white, tan, or light brown.own.

Precipitated Crystalline Precipitated Crystalline RockRockWhat are the crystals like?What are the crystals like?

• Monoclinic (tilted boxes), off-white, H = 3.Monoclinic (tilted boxes), off-white, H = 3.

• Cubes, transparent to dirty brown, H = 2.5Cubes, transparent to dirty brown, H = 2.5

• Acicular (long & narrow), off-white, H = 2.Acicular (long & narrow), off-white, H = 2.

BrecciaBreccia

• Coarse grainedCoarse grained

• Made of sharp pieces Made of sharp pieces of other rocks.of other rocks.

– This rock formed near This rock formed near the place where the the place where the other rock weathered other rock weathered into pieces.into pieces.

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ConglomerateConglomerate

• Coarse grainedCoarse grained

• Made of rounded Made of rounded pebbles and rockspebbles and rocks

– This rock formed from This rock formed from other rock bits that other rock bits that weathered out and weathered out and were worn smooth as were worn smooth as they travelled a long they travelled a long distance in fast water.distance in fast water.

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SandstoneSandstone

• Coarse grainedCoarse grained

• Made of sandMade of sand

– This rock is made of This rock is made of sand. If you look at the sand. If you look at the sand grains, you can sand grains, you can tell whether the sand tell whether the sand was in a beach, a was in a beach, a stream, a glacier, or a stream, a glacier, or a desert.desert.

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CoquinaCoquina

• Made of shell Made of shell piecespieces

– This rock formed in This rock formed in warm, shallow warm, shallow ocean waters, ocean waters, somewhere below somewhere below the low tide level.the low tide level.

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PeatPeat

• Made of plant piecesMade of plant pieces• Soft and crumblySoft and crumbly

– This rock formed in a This rock formed in a swamp or bog, swamp or bog, where still water where still water without much without much oxygen kept the oxygen kept the plant remains from plant remains from decaying completely.decaying completely.

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ChertChert

• Fine grainedFine grained• Hardness = 7Hardness = 7• Conchoidal fractureConchoidal fracture• Lighter colorsLighter colors

– This rock formed This rock formed from dissolved from dissolved quartz solutions.quartz solutions.

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FlintFlint

• Fine grainedFine grained• Hardness = 7Hardness = 7• Conchoidal fractureConchoidal fracture• Darker colorsDarker colors

– This rock formed This rock formed from dissolved from dissolved quartz solutions.quartz solutions.

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HaliteHalite

• Cubic crystals to Cubic crystals to massivemassive

• Transparent, clear to Transparent, clear to brownish.brownish.

• Hardness = 2.5Hardness = 2.5

• Rock salt.Rock salt.

– This rock precipitated This rock precipitated out when an ocean or out when an ocean or salt lake dried up.salt lake dried up.

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CalciteCalcite

• Monoclinic (“crooked Monoclinic (“crooked box”) crystalsbox”) crystals

• Hardness = 3Hardness = 3

• Transparent to dirty Transparent to dirty brownbrown

– This rock precipitated This rock precipitated out from solutions, out from solutions, often in groundwater.often in groundwater.

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GypsumGypsum

• Acicular (“needle Acicular (“needle like”)like”)

• Hardness = 2Hardness = 2

• White to dirty brownWhite to dirty brown

– This rock formed from This rock formed from solutions, often in solutions, often in semi-arid regions.semi-arid regions.

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CoalCoal

• BlackBlack• Massive or flat Massive or flat

layerslayers• Sooty (lignite) to Sooty (lignite) to

glassy (anthracite)glassy (anthracite)

– This rock forms from This rock forms from compressed organic compressed organic materials like peat.materials like peat.

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ShaleShale

• Dull and softDull and soft

• Flat layers or Flat layers or massivemassive

• Dark colors.Dark colors.

– This rock formed from This rock formed from clay minerals, usually clay minerals, usually in still water.in still water.

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LimestoneLimestone

• DullDull

• Hardness = 3Hardness = 3

• Fizzes in acidFizzes in acid

– This rock usually This rock usually forms in fresh water forms in fresh water or warm ocean or warm ocean water.water.

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