Google "Brussels Cornet Vase".
Belgium was not the only country with potteries making this style and - inevitably - they were also made in the Far East for Western importers. I would expect it once had a sticker on it that would have helped identify it further, but the '1821' is unlikely to be a date and it's likely to be from the 1900s.
The fleabay listing above is a 'buy it now' price and you can probably guess what my opinion is of that as a realistic value! I would be thinking more like $20-30