Name: _________________________
Date: __________________________
Flynt - ____ Period
____th Grade Science
Sedimentary Rock Classification and Identification Chart
CHEMICAL
Forms from
chemical
precipitation
and
evaporation.
BIOLOGIC
Forms as result
of accumulation
of organic
material or
biologic activity.
COMPOSITION
ROCK NAME
>2 mm
rounded quartz, feldspar and rock fragments (pebbles, cobbles, and boulders)
Conglomerate
>2 mm
angular quartz, feldspar and rock fragments (pebbles, cobbles, and boulders)
Breccia
1/16 - 2 mm
quartz>feldspar (sand-sized grains)
Sandstone
>1/16 mm
feldspar>quartz (sand-sized grains)
Arkose
<1/16 mm
quartz, clay minerals
Siltstone
(Mudstone, Shale)
<1/256 mm
quartz, clay minerals
Claystone
silica (quartz)
Chert
dolomite
Dolostone
calcite
Limestone
halite
Rock Salt
gypsum
Rock Gypsum
loosely to densely compacted diatoms shells, sponge spicules, radiolarian
shells or other marine fossils made from silica (quartz) and cemented with
silica
Diatomite
(Diatomaceous Earth)
and Fossiliferous Chert
loosely compacted organic material and plant fragments, typically brownish in
color
Peat
densely compacted organic material and plant fragments, typically black in
color
Bituminous Coal
calcite, micro-skeletal fragments
Chalk
calcite, almost entirely shell and skeletal fragments
Coquina
calcite with some shell and skeletal fragments
Fossiliferous Limestone
dolomite with some shell and skeletal fragments
Fossiliferous Dolostone
Variety of Textures
CLASTIC
Forms from
broken pieces
of weathered
rock (clasts).
TEXTURE/
GRAIN SIZE
Crystalline or
Massive
Texture
TYPE
Name: _________________________
Date: __________________________
Flynt - ____ Period
____th Grade Science