Panning
One simple way of finding heavy materials in sand and rubble is to "pan" the materials. Panning is a process of allowing water to work heavier materials to the bottom of a pan while allowing the lighter materials to wash away. This exploration will allow the learner to practice finding heavy bird shot or BB's from a sand mix. For more information about panning for gold see: see http://www.goldfeverprospecting.com/
Preparing Materials
Use a source of sand that can be panned. This can be any grade of sand from fine to rough. "Salt" the sample by adding either bird shot from a shot gun shell, BBs or any small metal shavings. You can use a file to make a small amount of copper shavings. These work well and stand out nicely after a panning process.
Exploration
Place a small amount of sample in a pan. You can use a real gold pan or a regular pie tin. The real gold pan has ledges that trap the heavier materials more easily. A regular pie tin works fine and you can have good success with simple materials. Gold pans are reasonable and can be ordered online easily, but pie tins are generally in the cupboard.
Put a few inches of water in a large tub. Using the tub of water, gently swirl the pan and rock it back and forth and allow the lighter sand particles to fall off the edge. The idea is to allow the heavy materials time to work downward and the lighter materials to gradually wash away. See the youtube video listed to see the typical action you can use to settle the heavy materials to the bottom: https://www.youtube.com/watch?v=ZCL6FKQZyoM
With repeated rocking motion and practice, copper fragments, or whatever you have "salted" the sand with, will remain. The copper filings will yield a small about of “color” in the bottom of the pan.
Use the STEM Notebook to record findings. Learners can write about the panning process in their own way, either as a description or a narrative. The report in the Notebook can be used as the basis for other forms of communication--speaking or a dramatic reenactment.
Technology of Gold Panning
Panning is labor intensive. If you have ever tried this in a running creek you notice a couple of things rather quickly. One, the water is generally cold and you have to get wet. Two, you have to lean over all day moving the pan back and forth. It is hard work!
As the search for gold brought small riches to some, those that developed more sophisticated technologies reaped bigger and faster benefit. Sluice boxes are one way early miners found greater yield for their effort while using water to separate the gold.
Here is one is a design anyone could make: https://www.youtube.com/watch?v=VC4W6x9VlBk
Larger industrial efforts use the same concept with heavy machinery and larger machines. See https://www.youtube.com/watch?v=Bo_EJpUlOwk for an overview of one company's method for using technology to find as much gold as they can as fast as they can.
Content Learning
The chemistry of gold and other "native" metals such as copper, lead, silver and many others can be explored. See http://rlayton.net/rocks/16.html The history and nature of the metal gold is a fascinating study in itself.
