Recent find

Bottle cap that I found last Wednesday. It was connected to the broken of neck of a bottle. The neck was maybe an inch long before flaring out into a rectangular bottle of indeterminate size, but possibly in the area of being
1 to 1½ inches thick. I am hoping that the marking on top is enough for an identification. Center circle is the size of a nickel. Side profile shows that the center of the cap is raise although I'm not sure if that is by design or by having been frozen with the contents still in the bottle. Please help if you can. Thank you.