Unidentified massive cut stone in middle of old woods

Found large square stone in woods near creek

These pictures do it no justice but my partner and I found this at the base of a long gone tree. Just a few yards from an old creek deep in the thick stuff in WNY. It took us over an hour of digging together just to uncover it enough to see it entirely. Worth noting that the two of us together using wedges and a makeshift lever were barely able to rotate it on its side 90*. Easily weighed at least 300 lbs but was perfectly cut with still distinct edges. The colors were magnificent but we don't know what it is. I believe this cut stone was placed where it was found for some significance. Hoping to go back to retrieve it as soon as possible. Will definitely need a durable utility cart to retrieve it safely. Someone please help us try to ID this treasure or provide some insight.