Our little lady has a fascination with all things sparkly, crystal like, and remotely scientific. So, one day she came to me with a picture and asked if we could grow our own stalactite. Here is our step by step guide of how to do it.
First of all you will need: 2 jam jars/glasses about the same size, baking soda, string, warm tap water, ruler, 2 weighted objects (we used random screws we had), and a small dish. You can also use some food colouring, but this is optional. We used red.
2. Fill both jars 75% full of very warm water.
3. Add one teaspoon of baking soda to a jar and stir until it is dissolved. Add again and keep repeating until the stirring does not dissolve the soda anymore. Make sure you count how many teaspoons you used, and add the same to the other jar. Stir until dissolved.
4. At this point we added food colouring into the mixture.
5. Multiply the height of the jar by 2, and add 20cm onto that. Then measure a piece of string to this length and cut. Tie the screws onto each end.
6. Wet the string with clean very warm water and place into the water, one end in each jar.
7. Place a small dish between the jars and place somewhere where they won’t be disturbed. It is important not to touch the stalactite crystals while they are growing or you might disturb their growth and break them.
Stalactites are found in caves. Ground water carrying dissolved calcium carbonate and other minerals seeps through rock cracks and into the underground caves. As the water travels over the ceiling to the cave, it reaches a low point where it drips. As it drips the minerals and calcium carbonate are deposited onto the ceiling. These build up and harden over time, creating the spike like structure hanging down called the stalactite.
As with any true science experiment, it doesn’t always go to plan!! Our crystals grew along our string but didn’t do any significant growing downwards. However, when we pulled the string out of the jars, we had beautiful crystals that had developed around the ends!! This little experiment is very simple to do, so perfect for little people wanting to make and watch the formation of their own stalactites, or in our case just some sort of crystals!!!