OK, this if entirely off-topic, but is a pet-peeve of mine...
Silicon = the raw element Si. Commonly used as the solid crystaline substrate for microchips (i.e. a "silicon wafer").
Silicone = the stretchy/rubbery stuff that earphone pieces, female enhancements, and window caulking are made from.
Two different things. Again, sorry for the rant, but it seems that everyone gets these exactly opposite when posting. You want the "silicone" pieces for your earbuds
are what I am using with my apple headset, even tho I still have the original tips. They seems to stay in my ears better, and improve the bass response a bit. You can get them at best buy for I believe $8.99