The Motley Fool - Just like the chocolate purist in those old ads who protested the delectable combination, coal investors protested CONSOL Energy's (NYSE: CNX - News) deeper dip into natural gas Monday with a 10% sell-off, dropping shares beneath $49 apiece. Although swallowing fossil fuels is never a good idea, investors may wish to 'taste' this unique combination of fuels before protesting themselves.