Cave Chandeliers

In our last experiment, Candy Crystals, we talked about where crystals came from.  This experiment is another type of crystal formation that we thought about.  On the week of Thanksgiving break, we decided to demonstrate another formation of crystals using this experiment. What is it? Well it demonstrates the idea of stalactite and stalagmite.

Lab materials you will need:

• Epsom salts
• 2 small jars, (Many I've seen have used mason jars, we decided to go with baby food jars.)
• string (Use cotton yarn/string it works the best)
• scissors
• 2 washers
• spoon
• ruler
• paper
• water
• tray or flat container

[Step One]
Fill both jars  two-thirds (2/3) of the way with Epsom salts.


[Step Two]
Fill the jars halfway with hot water.

[Step Three]

Stir the mixture.  Saturate the water with Epsom.  When the water cools down, add Epsom 1/4 of the way.  Then, add a little more water until the jar is 3/4 full.  The added Epsom salt should not dissolve in the water.  Mix the solution enough times to see whether or not it will dissolve. 

[Step Four]

Cut a piece of string, 24 inches (60 cm).   Then, tie a washer to each end of the string.

Soak the string in Epsom Salt solution. This does not need to soak long, but soaking allows the crystals to grow. This is considered the seed crystal.


[Step Five]
Place one washer in each of the jars.  Let the washers rest on top of the undissolved crystals. (Our jars are pictured half full here, but since have had water added for better results.)

[Step Six]
Place a piece of paper between the jars.

[Step Seven]
Position the jars so that the string hangs between them with the lowest part of the loop about 1 inch (2.5cm) above the paper.

Now allow the jars to stand undisturbed and out of any draft for one week. Water will drip from the center of the loop onto the paper.  A hard, white crust will form on the string and grow downward as the time passes.  A mound of white crystals will build up on the paper beneath the string.

Make sure to place this experiment in a container, such as a pan or baking sheet; the water will penetrate through the paper and spread all over the counter.

There will be an additional blog explaining Cave Chandeliers.