Crystal gardens are a fun project for children who are learning about geology. By growing a crystal garden, children can learn how solid crystals are formed from a liquid solution. Crystals are easy to grow in a variety of colors, sizes and shapes. Table salt and Epsom salt are both useful ingredients of crystal gardens. With some water and salt, you can create a small crystal garden in a few hours and grow large crystals over a few days.

...
Sugar crystals make lovely crystal gardens.

Table Salt Garden

Step 1

Heat 1 to 2 cups of water to boiling and transfer it to a mixing bowl. You can heat the water in a microwave or on a stove.

Step 2

Pour equal amounts of table salt, ammonia and bluing into the water, stirring as you pour. For example, for every 1 cup of water you use, add 1 cup of salt, 1 cup of ammonia and 1 cup of bluing. Stir until you saturate the water and no more salt will dissolve. You can add more salt as necessary.

Step 3

Place a rough rock into the bottom of a glass jar or bowl and pour the saturated solution over the rock. The rock will give the crystals a place to start growing. You can also use frayed cotton string or a seed crystal of the same substance if you do not have a rough rock. Tumbled, or polished, rocks do not work well for crystal gardens.

Step 4

Place the jar on a counter at room temperature. Check the solution in six hours. Salt crystals will begin to form quickly, and increase in size over the next three days. Let the solution sit until the crystals are as large as they will grow. You will know that the crystals are finished growing when they do not increase in size over a 24-hour period.

Step 5

Pour any remaining solution out of the jar or bowl once the crystals are fully grown.

Epsom Salt Gardens

Step 1

Heat 1 to 2 cups of water and transfer it to a mixing bowl. Do not boil the water.

Step 2

Pour an equal amount of Epsom salt into the water, stirring as you pour. For example, for every 1 cup of water you use, add 1 cup of Epsom salt. Stir until you saturate the water and no more Epsom salt will dissolve. Add more Epsom salt to the solution as needed.

Step 3

Pour the saturated solution over the rock. The rock will give the crystals a place to start growing. You can also use frayed cotton string or a seed crystal of the same substance if you do not have a rough rock. Tumbled, or polished, rocks do not work well for crystal gardens.

Step 4

Place the garden into the refrigerator. Check the solution in two to three hours. The Epsom salt crystals will begin to form quickly. Let the solution sit until the crystals are as large as they will grow. You will know that the crystals finished growing when they do not increase in size over a 24-hour period.

Step 5

Pour any excess solution out of the jar or bowl once the crystals are fully grown.