Science for Kids: Rock Crystals

Rock Crystals

We had a blast creating crystals with our latest science experiment.

Crystals are three dimensional structures where the molecules form together in a repeating pattern. This experiment doesn’t create instantaneous results but instead you gradually see the crystals form over a period of a week. My son was very excited to see the crystals grow day by day.

The first you thing you need to do for this experiment is a collection of rocks. We gathered rocks of different sizes, shapes and colors.

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Materials Needed for the Rock Crystal Experiment

Once you have your rocks collected, you can gather your other materials from around the house. Here’s what you’ll need:

  • non-metal pie pan (you don’t want to corrode your pan!)
  • your collection of rocks
  • 2-3 tablespoons salt
  • 1/2 cup warm water in a pitcher
  • spoon

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Once you have all of your materials gathered, go ahead and place the rocks in a single layer in the pie pan.

Next, add the salt to the warm water and stir it until it dissolves.

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Once the salt is dissolved, you simply pour the salt mixture over the rocks.

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Now, you need to figure out a good spot to place the pan. The crystals will need direct sunlight to form. We decided to place our pan outside on our patio table where it received direct sunlight for several hours each day.

Here’s what the crystals looked like after one day.

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We checked them everyday, sometimes several times a day!

Here’s what they looked like after 3 days. You can really see them now!

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Rain, rain, go away! How our experiment was nearly ruined!

We had an unexpected day of rain that nearly ruined our experiment. The crystals had disappeared but we decided to leave it out for a few more days to see what would happen. My son was very disappointed that the crystals were gone but quickly perked up when I told him we could redo the experiment if the crystals didn’t reform.

Well, we didn’t have to redo the experiment. The crystals came back! We were delighted to see that the crystals continued to form after the rain.

We had planned on continuing with the experiment for exactly one week, but we ended up keeping them for 10 days due to the rain.

Here’s what they looked like on the 10th day.

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Science Concepts Taught in the Rock Crystals Experiment

Here’s a list of some of the science concepts/terms you can discuss with your little one”

  • crystal formation – what are crystals? how are they formed?
  • solution – what is a solution? how do you make a salt solution?
  • dissolve – what does it mean to dissolve? can salt dissolve in cold water or do you need warm water?
  • evaporate – what does it mean to evaporate? what evaporated in this experiment?

Have fun experimenting!

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  1. says

    This would be a lot of fun!

    Thank you for stopping by the Thoughtful Spot Weekly Blog Hop this week. We hope to see you drop by our neck of the woods next week!

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