SAND LAB
name _________________
Date _________ hour ___
Sand is sediment defined as having a size between .06 and 2 mm. The history of sand may be determined
by studying the following:
MINERAL CONTENT
Determining the mineral content may help determine where the sand came from. Since sand grains are so
small. color is the best property. The following is a GENERAL key to minerals in sand:
clear ; glassy = quartz
red= hematite (dull), stained quartz (glassy)
black = magnetite (magnetic), biotite (flaky), hornblende
white = shells* (soft, angular, fizz?), plagioclase
brownish/yellow = limonite, shells (fizz)
pinkish= K-feldspar, shells (fizz) quartz may be stained a reddish-pink (clear, glassy)
orange- stained quartz (clear, glassy)- include with other quartz, or plagioclase if opaque
green = olivine
GRAIN SIZE
Large grains are young and have not traveled very far from their source. Small grains are usually very old
and have been weathered and eroded for a long time. A general key to grain size is:
coarse = greater than 1 mm
medium = 1- .5 mm
fine= less than .5 mm
To determine grain size use the sand cards at your lab station.
SORTING
This refers to the range of sizes in your sample. If sand is well sorted, it has been moved by waves for a
long time and is far from where it formed. Poorly sorted sands are found close to where they formed. Use
the following pictures to determine if the sample is well, moderately or poorly sorted.
Well sorted
moderately sorted
poorly sorted
SHAPE
Water will tend to make sand rounded and wind tends to make sand angular. Rounded sand is also older
since it has been polished more by erosional processes. Use the pictures on the sand card to determine the
roundness of a sand sample:
ORIGIN
Where the sand originates from is a key to its history.
In Northwestern and northeastern North America beaches are composed of minerals derived from the
glaciers. This creates a mixture of various minerals. Granite is the predominate rock source
Sand may also have volcanic origins. These sands are mainly found along the Pacific Northwest and
volcanic islands (Hawaii).
Sedimentary sandstone, composed mainly of quartz, is the predominate rock source in the Southern
States.
Biogenic sand (shell and coral) is generally found in warm climates such as the Caribbean or Mexico.
These contain shell, coral and red algae.
SAND LAB
Study 4 different sand samples under the microscope. One must be from Michigan, another desert and
an ocean. Place a pinch of sand on a Petri dish. Return the sand back to the original container when you
are finished. Use the terms on the back side of this sheet to fill in the data table below:
AREA
GREAT LAKES
DESERT
OCEAN
UNKNOWN #
sample name
mineral names
% of each
size (C, M, F)
Shape
Sorting
other
properties
After you have examined the sand samples, answer the following:
1. Determine if your unknown was from a Great Lake, ocean or desert. Explain your reasoning.
2. Which sample has the most angular grains? ________________
Is this what you would expect?
Explain why or why not
3. Which sample has the most variety of minerals? ______________________
Explain why this is.
4. Where does sand fit into the rock cycle?
Explain your reasoning.
5. What is the best way to distinguish ocean sand from Great Lakes sand? (not shells)
6. What is the best way to distinguish desert sand from water sands? Explain why.
7. Give two reasons to explain why most sands have so much quartz in them.