Monday, March 31, 2008

Growing Crystals

When my children woke up today, their first stop was the dining room table to check on our crystal experiments. It made me smile to see their enthusiasm for it. Before I got serious about getting a little organized about school so we could do more experiments and projects, their first stop would have been the TV or computer.

Here is a close up of our salt crystal garden this morning, after about 24 hours of growing. My daughter noted that it looked like coral. I have to agree. These crystals are very fine and held together by the bonding action of water molecules. The slightest touch and they smoosh. They were grown on a charcoal briquette sitting in the growing solution. On the charcoal, we had dripped food coloring so it would color the crystals as they grew. Their natural color is a white with areas of brownish red.


Despite coating the bowl with vaseline to prevent it, crystals also grew up the sides of the bowl (we used a pasta bowl). They ended up being a pretty off white-aqua color. They are now growing faster than the intended garden and falling over the edge of the dish.

We also grew alum crystals. Here is the bottom of the dish this morning. Alum grows fewer, larger clear crystals which are much more sturdy than the salt garden. You can see them in the bottom of the dish.

Here is a close-up of one of the alum crystals. It is about 1/8th inch in size. These crystals are obviously strong enough to handle (since I got it out of the dish) but can still be easily broken.

We enjoyed this experiment. We want to grow another salt crystal garden but with red and yellow food coloring. We also want to take some of the alum crystals and see if we can use them as seed crystals...put them in new growing solution to see if we can get bigger crystals formed with them.

I'm also hoping to try making some sugar crystals (rock candy). My understanding is that without slowing the cooling process, they'll make smaller crystals than you can buy commercially. My kids have never seen rock candy. Anyone know where I can buy some?

I would also like to set up an experiment to make stalactites and stalagmites. I need to buy some Epsom salts for that one. While we're playing with Epsom salts, I may as well make some Epsom salt crystals too.

All these crystal experiments came from this website.

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3 Comments:

Kysha said...

We did this last year with CLP science and ours did not turn out as pretty as yours. Ours was also titled "Growing Gems" but looked totally opposite from gems. LOL Yours turned out so great. I bookmarked the link also. Thanks!

Cocoa said...

These look like fun! With as many years as we've been homeschooling you'd think we'd have tried this already. I think now is a good time to do it!

Christina said...

Thanks for the ideas, JoAnn! Your crystals look awesome! We were going to do the salt crystals until I realized that I'm out of salt! I just added it to the grocery list, so we should be doing salt crystals soon!!