Growing Crystal Hearts

I've been trying to do more science process activities with the class lately, which has pushed me to try some classic experiments that I've never actually done as a teacher before. I always get a little nervous about how things are going to turn out, but growing these crystal hearts turned out to be so simple with awesome results. I followed the instructions found here to try this out, although there are a lot of different versions of this activity online.

First, we prepared the hearts and other materials.
I made the hearts by cutting a pipe cleaner in half, bending it for the bottom of the heart, forming the two curves at the top, and twisting the middle together. I also tried some smaller hearts, but those ones didn't turn out as well once the crystals formed.

Instead of using separate glass jars for each heart, I used a cheap plastic bin that would fit all of our hearts at once.

We could see some changes happening withing about an hour or so after setting them up, but let them sit until the next preschool day.

I might have saturated the water a little too much, because a very thick layer of crystals formed on the bottom of the bin as well. A few hearts ended up sticking to that a little, but came off with some careful pulling. We were all impressed with the beautiful crystals that formed- very hard, white, and sparkly!

The bottom layer of crystals came out of the bin pretty easily, and I saved the pieces for some further exploring later. We ended up using it for painting...