"Envy Versus Anger" by Paul Krugman at the NYTimes

[starroute]

6. Envy is when you wish you were someone -- anger is when you're mad at them

It's possible to have a mixture of both. You can envy someone who has a beautiful house or expensive car that you'll never be able to afford while being angry at them for their selfishness and lack of concern for the less fortunate. But that doesn't make either emotion a version of the other. And you could envy, say, an entertainment or sports figure while being profoundly grateful for the pleasure they've given you.

And since you mentioned it, I've just done a little googling on those efforts to categorize basic emotions -- and envy doesn't even seem to be included. It apparently isn't visceral enough but is more dependent on complex social relationships.