Notes from the Field...

Here’s a tip for keeping Mock Rocks breakable, even in very arid conditions. Our thanks to Wendy Swandal from Chief Joseph Elementary School in Great Falls, Montana, for the question and her efforts to remedy a dry situation.

On January 14, 2010, Wendy sent this e-mail to foss@berkeley.edu.

I am currently teaching Investigation 1, Mock Rocks, in Earth Materials. I made the rocks seven days prior to the lesson and the rocks were as hard as bricks. The third graders could barely break them in half. Then they struggled breaking apart the gray material. What did I do wrong? Thanks for your help.

Hi,

Is the air fairly dry there in Montana right now? If it's anything like where I am in Ohio, we are really arid right now. So I don't think it's anything you did wrong. I think the dry air was probably the culprit. Next time, when the rocks reach the desirable dryness, you might want to pack them into a zip bag so they don't lose any more moisture and turn into real rocks. If you want to use this batch of rocks with your students, put them in a zip bag, spray lightly with some water, close the bag up overnight, and see if they're more breakable the next day. (Let me know if that works; if so we'll make sure to add a note in the Teacher Notes on FOSSweb.)

Thanks for your question.
Sue Jagoda
FOSS Developer (in Avon Lake, Ohio)

Good Morning! Yes, putting the rocks in a Ziploc baggie with water worked well. I did get too much water on a couple of pieces causing them to get soggy. I appreciate your help. Have a super Friday!

Wendy Swandal