First of all, I'm a Realtor, and I'm on the committee for my neighborhood to negotiate a better deal with the offers we have been receiving on Mineral Leases. That being said, there are many factors to consider here. One would be, when did you purchase your house? If it was more than a few years ago, chances are that when you purchased it, the mineral rights were transferred to you when you signed the documents at the Title company.. UNLESS IT WAS STATED OTHERWISE IN THE LISTING AND IN THE CONTRACT. There is a section in the Sales Contract that is called "Special Provisions". Unless it was specifically stated there that "Mineral Rights do not convey" or some similar language, then you should have them. Check your closing documents and contract, if you have them. Also, if you have a copy of your Deed, and it doesn't state otherwise, then you have them. For instance, we purchased our home about 4 1/2 yrs. ago and no where did it say that Mineral Rights DO NOT convey. It is also not in our deed, so they are ours (yee-haw!!). Unfortunately, you can't assume that you have mineral rights just because you are receiving offers in the mail from Leasing Companies! They companies should have done their due diligence in researching this prior to sending out offers, but they don't always! Now, if you have bought very recently, it is very likely that you don't have them. Retaining Mineral Rights is a trendy thing lately. It is hard to buy a house these days and to get the rights to Minerals in the sale. It does happen, but not frequently.
On another note, if you do have them.. hold out for a better deal and encourage others to as well! I'm not sure where you live, but our original offer was a $3,000 signing bonus per acre, and we are up to $10-12,000.. and still negotiating! There's much more to a good lease than a signing bonus though, but I'm sure whomever is in charge of that will find the best terms for everyone!
I hope that helps and wasn't too confusing! :) Let me know if you have any other questions!