Quick Lab – Sedimentary Rocks
1. Sedimentary rocks are classified as __________________, __________________ or
____________________ depending upon the type of material that composes them.
2. Clastic sedimentary rock is further classified by the __________ of the sediment they
contain.
3. A conglomerate has _____________ particles whereas ___________ has angled particles.
4. Limestone is the most abundant chemical sedimentary rock and is made of the calcium
carbonate mineral called _____________ which effervesces (fizzes) when in contact with
hydrochloric acid (HCl).
5. List the type of clastic sediments from smallest to largest.
____________________________________________________________________
Sample
Route Taken
Begin w/#4 for
this quick lab
1
2
3
4
5
Sediment Type
Pebbles, sand,
silt/clay, plant,
minerals
Rock Group
Biological,
Clastic, or
Chemical
Rock Name
Key to Rock Classification
1.
Does the rock contain visible
crystals?
Yes: Go to Question 2
No: Go to Question 4
2.
Are all of the crystals the
same color and shape?
Yes: The rock is a non-foliated metamorphic rock. Go to Question 13.
No: Go to Question 3
Are all of the crystals in a
mixed “salt-and-pepper”
pattern? (not necessarily black
and white)
4. Does the rock contain many
small holes or have a uniform
dark color?
5. Is the rock glassy?
Yes: The rock is an intrusive igneous rock. Go to Question 15.
No: The rock is a foliated metamorphic rock. If it is black and white
striped, it is granite gneiss. If it is not striped, go to Question 9.
6.
Does the rock have flat, thin,
uniformly colored layers?
Yes: Go to Question 12.
No: Go to question 7.
7.
Does the rock contain
pebbles, sand or small
particles cemented together?
Yes: The rock is a clastic sedimentary rock. Go to Question 14.
No: Go to question 8.
8.
Does the rock fizz when
dilute HCl is dropped on it?
Yes: The rock is a biochemical sedimentary rock. It is limestone.
No: The rock is extrusive igneous. It is rhyolite.
9.
Does the rock have large mica
crystals and have a scaley
appearance?
Yes: The rock is mica schist.
3.
Yes: The rock is an extrusive igneous rock. Go to Question 10.
No: Go to Question 5.
Yes: The rock is an extrusive igneous rock. It is obsidian.
No: Go to Question 6.
No: The rock is garnet schist.
10. Does the rock float in
water?
Yes: The rock is pumice.
No: Go to question 16.
11. Does the rock contain fossils?
Yes: It is a clastic sedimentary rock. It is shale (Carboniferous)
No: Go to question 12.
12. Is the rock powdery and
gray?
Yes: It is a clastic sedimentary rock. It is shale (Argillaceaous)
No: It is a foliated metamorphic rock. It is slate.
13. Can the rock scratch glass?
Yes: It is quartzite.
No: It is marble.
14. Does the rock contain small,
rounded pebbles?
Yes: The rock is a conglomerate.
No: The rock is sandstone. (If it has stripes, it is banded.)
15. Is the rock mainly dark in
color?
Yes: The rock is gabbro.
No: The rock is granite.
16. Does the rock have many
holes?
Yes: It is an extrusive igneous rock. It is scoria. If it is No: Go to
Question 17.
17. Does the rock have layers?
Yes: It is a biochemical sedimentary rock. It is coal.
No: It is an extrusive igneous rock. It is basalt.