Growing Crystals in Eggs - Baking Soda is the Winner!

Shortly before Easter Jo and I did a science experiment about growing crystals. Instead of the same old-same old rock candy experiment, we grew all different kinds of crystals in eggshells. You can see the link to the tutorial and the before pics in the previous post, but I thought I'd show some afters now that the water is all evaporated.

The most boring were the granulated sugar

 and table salt.

They just kind of hardened into one big chunk at the bottom of their shells. These might have been better if I had seeded the solution with some starter crystals - I don't know. But the others were pretty fabulous. Check out the gorgeous cubes of kosher salt.

And the smaller cubes of the ice melt. Some of the ice melt solution seeped out through hairline cracks in the shell and grew crystals on the outside too. Cool!

The powdered sugar made an even coating of small crystals.

But the hands-down winner was the baking soda solution.

The first picture in the post was also the baking soda egg. The solution seeped through cracks to form crystals on the outside of the shell (like the ice melt) but it also wicked up through the egg shell to form crystals on the entire cracked edge. And the inside of the shell was coated with teeny-tiny little crystals. So pretty.

The eggs are pretty and all - but as Jo and I examined the eggs, took pictures, and compared the final results to Jo's predictions, Jo said, "You know what I think happened? I think all the water we added the the crystals evaporated away and it left just the crystals behind." Which led to a talk about how to get salt from ocean water, the salt caverns near Krakow, and the expression "earning your salt." We even took a salt quiz. Good geeky fun. :-)