You could probably get the gemstone thing happening with the right filtering (or mathematics a-la FFT)
As harsh as it sounds, Arduino is pretty much Lego for wannabe engineers. Don't expect too much beyond novelty applications from it
With that said, if you feel you have an interest in Electronics, it's really best if you start with an "Electronics 101" style book, the 'for dummies' series is great - words can't explain how important it is to have a basic understanding of electronics concepts prior to jumping onto the microcontroller bandwagon
...Of course if you don't give a damn about the field, and want to 'get down to business' in creating flashy things with wifi connectivity, then Arduino may just be your thing, especially if you're not looking to commercialize your creations
NB: I don't mean any offence to Arduino-lovers, I'm just not a huge fan of the fan-club - I've seen people install an off-the-shelf Arduino devboard into their vehicle, running off a linear regulator, which is attached to their ignition system via a shield. Complete and utter stupidity on so many levels.
