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Patricia Ann Riley Lincoln Park High School
2001 N. Orchard Street Mall
Chicago IL 60614
Students in grades 6 through 12 are to:
1. observe a variety of naturally occurring crystalline solids;
2. observe a variety of crystalline solids available in the supermarket,
drug store, or hardware store;
3. use watercolor techniques, wax crayons, and the saturated solutions of the
crystalline solids in objective 2 to paint a picture;
4. compare, write a description, and draw diagrams of the various crystals;
5. exhibit the completed paintings.
Demonstration set: Variety of naturally occurring crystals, such as quartz,
fluorite, citrine, amethyst
Per team of 4 students:
Crystal samples: Saturated solutions (Tempera paint added):
CuSO4.5H2O (Root Killer E) CuSO4.5H2O (Naturally blue; no paint added)
AlK(SO4)2 (Alum) AlK(SO4)2 (Yellow)
NaCl (Table Salt) NaCl (Green)
MgSO4.7H2O (Epsom Salts) MgSO4.7H2O (Red)
Per team of 4 students:
wax crayons newspaper magnifying glass/microscope
distilled water paint brushes 81/2" x 11" white construction paper
name labels paper towels large sheets black construction paper
small jars tape hot plates/hair blowers (optional)
1. Advance preparation: Make a saturated solution of each sample crystalline
solid (Root Killer E, Alum, Table Salt, Epsom Salts), using distilled water.
Be sure some undissolved solid remains at the bottom of each container; this
guarantees saturation. Add a small amount of powdered tempera paint to each
saturated solution, except the Root Killer E which is naturally blue in
color. Divide the paint solutions among enough jars for one set per team.
2. Pass around samples of naturally occurring crystals. Discuss what crystals
are, what they look like, where they are found, what they are used for, how
they are made. Have the students note the color, shape, size of the
crystals. Have them compare and contrast.
3. Explain to the students that they are now going to use a variety of
crystalline solids used in their homes to paint a picture. Demonstrate that
they first draw a crayon picture which they will fill in with a variety of
tempera paints dissolved in saturated solutions of the solids. Stress that
they should use a different brush for each color of paint. Emphasize that
the students are to stir the paint solutions each time they use them. This
will insure that seed crystals will be mixed with the paint. Also point out
to the students that they want to leave paint puddles on the paper.
4. Divide the students into teams of four and give each student a sheet of
white construction paper. When they finish their painting, they can either
let it air dry overnight or use a hot plate or hairblower; air drying is
better since slow evaporation produces larger crystals.
5. Now have the students examine with a magnifying glass samples of the
crystals provided at each station. They should consider shape, color, size.
They should write a sentence describing each sample's crystal and draw a
larger-than-life diagram of each.
6. Have the students examine their dry painting with a magnifying glass, write
sentences describing the crystals that have formed, and again draw diagrams.
7. Discuss what the students observed. Have them compare and contrast the two
sets of crystals: the reference set at their station and the crystals in
their painting. What happened to the crayons? Why were the crayons used?
How were these crystals formed? What effect did the paint have on the
crystals? How might the students extend the lab?
8. Have the students mount their paintings on a sheet of black construction
paper with tape and affix a name label under the painting. Display the
paintings as at an art exhibit.
9. Have the students write a paragraph summarizing what they observed and
learned. This and their descriptions will serve as a lab report.
Students will be assessed on completing and displaying their painting and on
submitting a lab report, consisting of a sentence description and diagram
for each reference crystal and each crystal in the painting and a paragraph
summarizing their observations and conclusions. This will count as a full
lab grade. Content of the painting itself will not be graded. The teacher
should monitor the work in progress to insure that gang signs and other
unsuitable content are not used, but should not otherwise censor the work.
Students will also be assessed on the material on the next test.
1. Different substances produce different crystals. The crystals of a
particular substance will have a fixed shape and color; their size depends
upon the amount of time allowed for growth. This means that substances can
be identified by their crystals.
2. One way to form crystals is through the evaporation of a saturated solution.
3. The paint does not alter the crystal shape or color. It did coat the
outside of the crystals and act as a glue to help the crystals stick to the
4. All of the solids used in the painting dissolve in water and therefore will
not normally be found in nature. Naturally occurring crystals do not
dissolve in water and must be formed by a different method. One possible
method would be crystals forming as a molten liquid cools. This would
happen in places such as volcanoes and lava flows.