Tuesday, March 10, 2015

Is it possible to grow crystals inside the eggshells? This is what we set out to discover by trying to grow egg geodes with different crystal forming materials.
Growing Crystals In Eggs with 4 different crystal forming solutions

Don’t Believe Everything Pinterest Tells You

A few weeks ago I found this neat “instructographic” for making eggshell geodes. It all seemed very nice and clear, and I thought that it would be a great project to surprise my daughter with on her return from Germany. So a week before her return I followed the instructions and set up 4 solutions with 1/4 cup of water and 1/8 cup each of salt, sugar, Epsom salt, and Borax. I was envisioning pretty crystals forming inside the eggs as promised:
Eggshell Crystals - Day 1 All I can say to the instructions after trying this experiment is “As if!” After a week of standing undisturbed, my eggs still had way too much water in them and not enough crystals.

Egg Shell Crystals - Day 7 Eggshell Crystals Revealed

On Day 7 I poured out remaining solution and cracked the eggs open:

Eggshell-crystals What Have We Learned?

  • Some crystals formed with Borax (aka alum) that is known as the best substance to grow crystals at home.
  • Salt produced some crystals on the rim – this solution was most over saturated with 1/4 cup of water and 1/8 cup of salt, and I put the remaining salt in the solution on the rim. That seeding seemed to help crystal growth on the rim of salt eggshell.
  • I think that Epsom Salt and Sugar both were not saturated enough to produce crystals.
  • Also, I think that in all eggs crystals had a hard time taking because there was no “seed”. The other instructions for egg deodes that I found online included “seeding” an eggshell by first putting some glue inside and sprinkling crystals on it, then waiting for the eggshells to dry. This is perhaps what we will attempt next year.

Your Turn

STEM Activity for kids - growing crystals inside the eggshells
Have you ever tried to grow crystals in eggshells?

More Science for Kids

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An Almost Unschooling Mom said...

You had better luck than we did :) We tried it once, in connection with real geodes, but someone knocked the eggs over, and dumped out the liquid before the crystals formed.


maryanne @ mama smiles said...

The borax looks pretty good. I think under-saturation is one of the most common reasons for crystal failure.

Heather H said...

Thanks for being the pinterest guinea pig on this one. My kids have been interested in geodes lately - we'll have to try this ourselves.

maryanne @ mama smiles said...

We haven't tried this, but I have heard that seeding makes a big difference.