BACKGROUND:
Understanding sedimentary rocks requires observational skills. The best
way to look at sand is with a microscope. If you do not have microscopes use
magnifying lenses. However, they will not make the sand look as spectacular.
Review with students that sand on the beaches may someday become rock if
it becomes squeezed and cemented together. The sand on the beaches, lakes,
or rivers reflects the source or "mother" rock. The mother rock
erodes and creates "baby" rocks (sand). The baby rocks have
similar characteristics of the mother rock. However, the river or ocean
moves the baby rocks sometimes far from the source. Other times the sand
reflects the rocks that are eroding nearby.
PROCEDURE:
- Set up the microscopes before the students look at them. An easy way
to observe sand is to get tape and put a small amount of sand on the
sticky side, this will prevent the sand from spilling. You may also want
to use "dot" stickers and put sand grains on the sticky side
and then paste the other side to an index card.
- On the microscope use the reflecting stage. Place the specimen under
it and have the children look at the sand. You may want to use tape or a
round Avery label to pick up sand on the sticky side. You can then glue
it to an index card so it is easy to look at. Children are amazed at how
large the sand looks under the microscope. You may want to make a game
of this by setting up eight microscopes, making six samples of different
sands with duplicates of two samples.
- See if the children can find the sand samples that are the same. This
way they will make close, careful observations. You can use sand from
the Sand Kit if you select this option.
- Point out that the individual grains of sand can be different colors.
If two sand samples have the same colors (components) they probably came
from the same mother rock. These sand particles may be
"brother" and "sister."
