When I was on a business trip last fall, on my one day off (out of 12) several of us wandered towards Gatlinburg, TN for some sightseeing and hiking.
We found a rock shop and a colleague and I wandered in. It was filled with the basics that are found in the Great Smoky Mountains, but tucked in a box in the corner was a pile of plain grey rocks. Dolomite, the rocks are called. They sold for about $3 each and with the purchase was this piece of paper:
I took the rocks home and presented them to my sons -- who thought I must have hit my head or something to have brought them plain rocks.
Here are the two rocks in glass containers that I didn't plan to use again:
According to the directions, you add enough white vinegar to cover the rocks completely. I'll return to discuss this step.
Once you add the vinegar, you are to set the glasses in an area and leave them alone for "4 to 8 days" according to the directions I had. The vinegar was supposed to evaporate and doing so would leach the crystals out of the rock.
"4 to 8" days my foot. Here in Florida it was more like 25 days. We started this on December 12th and we didn't see any crystals until about January 15th. The pictures of the crystalized rocks are from January 30th. So let's call that 49 days.
I'm very sorry I couldn't get better picture of the finished crystals, I've been having camera troubles.
Let's talk about what went wrong here. First of all, I was supposed to leave the very top of the rock exposed and not cover it all the way. The crystals didn't start growing until the top of the rock was exposed...and apparently they would have started up right away if I had done that. Secondly, this is the coast of Florida. So evaporation rates are about half of what it would have been inland.
Do you want to try your own dolomite "flowering rock" experiment? Educational Innovations sells two-pound bags of rocks in assorted sizes for $8.95. You can see the instructions for this kit here, where it clearly states that you're to leave the very top of the rock exposed.
I will be revisiting this experiment on my own blog as the rock continues to dry out and I will be able to remove it from the glass.
