By;
Flor Hernandez
Gloria Pulido
Sedimentary Rock Identification Chart
sample
number
1
clastic/nonclastic
composition
grain size
structures present
rock name
Angular gravel,
Larger than 2mm
Fragmental
breccia
Rounded gravel
poorly sorted
Larger than 2mm
Rounded
Quartz breccias
conglomerate
Dark colored
heavy
amorphous
chemical
residues or
microcrystalline
nodules
Plant fragments
and/or charcoal
none
Layer like
ironstone
None
Dull dark brown brittle
rock
lignite
Organic material none
microcrystalline
quartz
Mostly sand
1/16 – 2 mm
Glassy
Chert (a siliceous
rock)
Mostly feldspar
arkose
Rock gypsum
Ironstone
Clastic
2
Clastic
3
Inorganic
4
Biochemical
5
Non-clastic
6
Clastic
7
Non-clastic
Gypsum mineral
crystals
None
8
Biochemical
Dark very fine
grained rock
Not visible
Gray, white or
colorless visible
crystals or
microcrystalline
Conchoidal fracture
9
Inorganic
Iron-bearing
None
Dark colored
micrite
By;
Flor Hernandez
Gloria Pulido
sample
number
clastic/nonclastic
composition
grain size
10
Inorganic
minerals crystals
Iron-bearing
None
minerals crystals
11
Clastic
none
12
Non clastic
13
Clastic
14
Clastic
structures present
rock name
Dark colored
Ironstone
Not visible
Breaks into block or
layers
siltstone
Microcrystalline
varieties of
quartz
Mostly clay
None
Conchoidal pressure
Ironstone
<1/16mm
Crumbles into blocks
Claystone
Mostly rock
fragments
1/16-2mm
Lithic sandstone
15
16
Clastic
Shell and shell /
coral fragments
17
Clastic
Ronded gravel
poorly sorted
18
Non Clastic
Gypsum mineral
crystals
19
Non clastic
Gypsum mineral
crystals
Mostly gravel
sized shells and
shell or coral
fragments
Larger than 2mm
fragmental
coquina
Rocks fragments,
rocks, quartz,
Breccia
None
Gray, white or
colorless
Rock gypsum
None
Gray, white or
colorless
Rock gypsum
By;
Flor Hernandez
Gloria Pulido
sample
number
20
clastic/nonclastic
composition
Iron bearing
Dark colored
minerals crystals heavy
or residues
amorphous
chemical
residues
grain size
None
structures present
Chemical
residues(limonite)
rock name
ironstone