I think it is pretty common Bill. I've always noticed a distinct scent after a rainfall. Different depending upon where I am, the type of rainfall and the time of year.

I don't like the term though, generally it's a nice scent (apart from spring-time in the city which just smells like exposed and melting dog poop) and petrichor doesn't do it justice.

I think it's the "ich" which sounds like "ICK" a sound of disgust.