How can you tell the difference between real chestnuts and buckeyes?

My in-laws have just purchased the property adjacent to ours, and upon inspecting the premesis yesterday, we found what looked to be a chestnut lying on the ground. I have no idea how to tell the difference between the two, and I know that humans cannot eat buckeyes. If this is a true chestnut tree, then we will keep it. If not, and it is a buckeye tree, we know we can cut it down. I just dont want to waste delicious chestnuts, if thats what they really are.

How can you tell the difference between real chestnuts and buckeyes?
I'd check around to see if the husks are still on the ground -- buckeyes (or horse chestnuts) come in husks that look like big, green morning-stars or maces, with evenly spaced spikes. Regular (edible) chestnuts come in husks that are more like sea urchins -- densely covered with thin, needle-like spines. Also, if you crush the leaves of the buckeye (wear gloves or do this with a stick or something), it will smell unpleasant because all parts of the plant are poisonous (contains a saponin compound called aesculin, which causes your red blood cells to explode) The wood of the tree is much softer than a real chestnut tree, and is a pale, almost white sort of tan color, while real chestnut wood is darker. If all you have to go by is the single nut with no spines (or cupule), you'd have to take it to your local garden center or horticulturalist for identification. Don't eat any until you're sure -- one horse chestnut probably won't kill you, but you won't be happy for a few days.
Reply:I'd take the chestnut to your local Arborist and have him/her advise you; I actually have 4 dogwood trees on my property; 2 bear a bumpy, cherry like fruit; I took it to my local guy and he advised me that it's a tart, edible fruit that certain Dogwoods produce and if I wanted, I could make "tart" jams or add to rice, or into stews...who knew?
Reply:Buckeyes are a real dark brown, where chestnuts are a light brown.