Loc: Michigan, USA
I recently won an auction on Ebay for fragments of elemental germanium (element #32) for just $5! This stuff can be really really expensive, and scoring these fragments at such a price was quite a deal!
"Why would I want it?" you must be thinking! Germanium, though it looks like a metal, is really a metalloid and somewhat brittle. It has a very interesting property, as though it has a metallic shine to it, at some infrared wavelengths, it is fairly translucent (2-15 micrometers). This means that I can place a piece of germanium in the path of an infrared light and the light will still shine through.
"So what? Us humans can't detect infrared with our eyes!" must be going through your head at this point! Well, here's where the fun comes in! If you didn't know about this little trick, you can have some new fun with a household remote control and a cell phone, whether you have germanium lying around or not!
Most cell phone cameras (so probably yours) DOES detect infrared. If you turn on your phone camera and point a remote control (television, DVD, etc) and press a button on the remote, you will see through your camera phone the infrared LED in your remote light up! How cool is that?!
In theory, when I have my piece of germanium, I should be able to do the same thing, but when I place the piece of germanium in the path of the infrared, I should still be able to see the infrared LED lighting up!