If I've learned nothing else about mid C19 glass I can recognize the earlier method of handle attachment. The wheel engraving is magnificent workmanship, some of which shows amazingly fine detail - the short, barely more than 1mm long hairs on the end of the insect's abdomen, and some of the tiniest possible marks on the flowers. Unfortunately, the 24 point star doesn't have quite the same accuracy. If it is genuinely period it's remarkably clean internally, the foot likewise - I've never bought a decanter with this probable age that wasn't stained inside. There are a few stones, and the handle looks real enough, so might be the pukka thing. Stands 10.75"/275mm tall. Date wise I'd go for c. 1850 give or take a tad - but have no idea as to origin, so if anyone would like to suggest somewhere as being more likely, I'd welcome all thoughts, and thanks for looking.
P.S. and the cost?? - you won't believe it........ just Sterling £2. in a local charity shop