The stamp shown was a work house with billions printed and saw service over a number of years. As such there are many varieties a few of which are less common than the others. The odds of stumbling across one a rare stamp are typically longer than winning a mega lottery. So it is always best to start with the assumption that any stamp you have is the most common variety.
The stamp shown above has a catalog value of 25 cents but market value is a few pennies. However if you are interested in picking up a new rewarding pastime, stamp collecting may offer you a lot of rewards. You can learn more about stamp here http://stampsmarter.com/1847usa/192...ntifier.html
Please also note that the stamps should never be mounted a shown. These old 'magic' photo album pages will eventual damage anything that is adhered to them.