A common trap

How delicious is the feeling of fine silicon crystals slipping twixt one’s foot digits - Anjana Ahuja, author of a Science Column, at the beach.

...like those little silicon bags that come in electronic equipment packaging - Ben Goldacre, on page 8 of Bad Science

I wore thick silicon gloves - Alex Renton, at a sweet factory

No no no. The first two mean "silica". The last means "silicone". All should know better. (The last has more of an excuse, since he's a food writer, but he used up his excuse by writing about "an algae".)