no easy way to tell subbit from bit coal. there are a few ways to determin if a coal could be sub bit. It will tend to be very soft, often more grey than black, crumbles easily and has a low heat output. Having said all that, there is no significant sub bit located in your area and what you have is not sub bit. There are many different qualities that different bituminous coals possess, few which make one coal a "better" coal than the next universally, but for home heating there are a few significant properties that will make your life easier. you want a coal with a high ash fusion temp (no clinkers), a coal with a low coke button which will prevent "bridging" in the firebox shortly after loading (the fresh coal melts together, not the same as a clinker) and high btu and low ash. In addtion there are other properties of certain bit coals that don't necessarily make them "bad" for home heating, but depending on your setup, perhaps less desireable. One is the volitile content, a high volitile content will lead to easier and faster ignition (not neccessarily short burn times) and more soot, another property is the ignition temp of the coal and volitiles and this can vary even among high volitile coals; A high ignition temp may lead to slow initial ignition, but can also lead to a fire going out if not kept hot thus leaving a firebox full of partially burnt coke. Most eastern KY coal is generally ideal for home heating bit coal. It has an average to low ignition temp, though releasing it's volitiles slowly, it also has high btu's and low ash with a high ash fusion temp (no clinkers) and is free-burning (no "bridging" in the firebox). If you don't like the properties of your coal, buy some from someone else and try it out. Always try and find the source (region, seam etc.) of the coal if they'll tell you and the properties- sometimes the retailers will have a proximate analysis on hand from the source/mine (sometimes not, you'll just have to try it to see how it works), if you are able to find out what type/source of coal works best for you, it will better help you shop around for price etc.