Hey RKinOI...
The bottle appears to be a "mallet" type of bottle, commonly used for rum. By the shape, I would say that it is just prior to 1800... 1780 - 1800 or so. The glass is very "sick" and it appears to be "free blown" meaning it is very old, black glass and was not blown in a mold of any kind. many of these came from England, Dutch... some from colonial America.
The bottle is not a "high dollar" find, unless it has a "seal" on the shoulder. Black glass, free blown mallets are in the $35.00 - 75.00 range depending on the type, age, color and condition.
Hope this helps,
Wayne