No, that is not my car windshield defrosting. It's not a photo of some weird mold, either. These are crystals my kids and I grew outdoors on the glass patio table this morning.

I didn't get up this morning and think, "Oh! It would be a perfect day to grow crystals on my table!" I was working on another crystal project (hope to post it later this week) and had some leftover solution. I had run my solution through a coffee filter to clear out undissolved solids (and dog hair that mysteriously worked its way into the solution) and recalled a tutorial for making quick crystals in the sun. It was warm and sunny outside, so I thought I'd set the coffee filter on the table to dry and maybe grow quick crystals. The filter turned out okay, but the solution we had accidentally spilled on the glass table produced these crystals. If a little solution is good, more is better, right? The kids started making little pools of solution across the table, some containing dots of food coloring. We made up other crystal growing solutions to try. In the end, the table was flooded with solution, producing a sparkling rainbow when the liquid hit the hot glass.



If you want to try this at home, I recommend using the following solution:

• 1 cup hot water
• 1/2 cup table salt
• 1/2 cup vinegar

Mix the salt, vinegar, and water. This solution is non-toxic. This is important, since your pets might help (mine did), kids will want to touch the crystals, and there is a good chance you will end up washing the solution onto your porch or yard. When you are done, definitely break out the garden hose, since any salt solution could corrode the metal on your table if left there indefinitely. The rate of evaporation will affect the size of the crystals. Fast evaporation will yield numerous tiny crystals. Slower evaporation (cooler temperatures, higher humidity) will produce larger crystals. Have fun!

Photo: My patio table. Note the lovely scratches in the glass. (Anne Helmenstine)