Aramis Antiques has dated this piece to the 1850s.
The base is star cut. The baluster neck base is cut in a graduated diamond design rising up the neck in slice cuts. The stopper, original and with a perfect fit, is diamond cut. There is a minuscule nibble at base of stopper (see photo). It does not affect the aesthetic or fit. This is a pretty and decorative early Victorian decanter for wine or fortified wines such as port or sherry.
Aramis Antiques has dated this piece to the 1850s.
You can view the stock and full dealer information on the Aramis Antiques Profile Page