My Mom bought this from a dealer that labeled it as a spindle whorl from the Chibcha tribe near Bogota, Colombia. It is supposedly 100BC - 100AD. It is in really amazing condition for something that old. The clay is a reddish brown and the dimensions are 1" tall x 1 1/2" wide. Does this sound realistic?
Due to their compact shape and small size, spindle whorls tend to survive longer and in better condition than other terracottas. I have several from that period or older. Whether yours is authentic or not, is best judged by an expert who can hold it and feel it (and smell it ).
I can't speak to the authenticity of your particular piece, but the world is full of pottery as old as & older than that. As AJ says, the small, compact, relatively thick walled items can survive very well.
