Crystal Gardens
Mad Science
Chemistry/Earth Science
Questions: What is a crystal? How do crystals form and grow? Do different chemical
compounds grow different crystals? How does crystal growth relate to the Water Cycle?
Experiment # 1 – NaCl Crystals
Materials:
 Styrofoam Bowl
 Plastic cup
 Food coloring
 NaCl (Table Salt)
 Tap Water
 Mrs. Stewart’s Bluing
 Pieces of Charcoal
 Plastic Spoons
Procedure:
Day 1
1. Break a piece of charcoal into several smaller pieces. Ask for help if you need it.
2. Put the charcoal pieces in the Styrofoam bowl. Write your name on the bowl.
3. In your plastic cup, mix 20 ml of water, 6 level spoonfuls of NaCl (table salt) and 20 ml of
Mrs. Smith’s Bluing. Stir to mix up. Not all of the NaCl will dissolve.
4. Pour all of you water/NaCl/Bluing mixture directing onto the charcoal pieces in the bowl.
5. Make observations on what you see.
6. After an 1 hr, record your observations again
Day 2
7. Record your observations
8. Add 6 more spoonfuls of NaCl to your crystal garden
Day 3
9. Record your observations
10. Mix 20 ml of water, 6 level spoonfuls of NaCl (table salt) and 20 ml of Mrs. Smith’s Bluing.
Stir to mix up. Not all of the NaCl will dissolve.
11. Pour this mixture into the bottom of the bowl (NOT directly on the charcoal and crystals!)!
12. Add a drop or two of food coloring to each piece of charcoal (Not required if you want
white crystals!)
Experiment #2: MgSO4 Crystals
Materials:
 Styrofoam plate
 Plastic cup
 Black construction paper
 Warm water
 MgSO4 (Magnesium Sulfate or Epsom Salts)
 Scissors
 Plastic Spoons
Procedure:
1. Use scissors to cut a circle of black construction paper so it fits in the bottom of your
plate.
2. In a plastic cup, mix 50 ml of warm water with 6 spoonfuls of MgSO4. Stir until the
MgSO4 is completely dissolved
3. Put the construction paper in the bottom of your pie pan
4. Pour the MgSO4 mixture over the construction paper
5. If you wish, add some drops of food coloring around the bottom of the plate.
6. Observe what the construction paper looks like and record your observations
The SCIENCE!
Water around the Earth is filled with different chemical compounds known as salts. The
amount of salt dissolved in water varies from almost none in fresh water lakes and rivers to
about 5% in the ocean. The Great Salt Lake in Utah has about 25% salt in it! As water
evaporates, some of the salt cannot be kept in the water and salt crystals form along the
edge of the water.
Crystals are how some minerals appear in nature. Have you ever looked at some table salt
under a microscope? Crystals come in many different shapes and colors. Each chemical
compound has it own unique characteristics.
This experiment can be done with many other “salts”, not just NaCl or MgSO 4. Try some
other salts at home!