I just purchased this temple jar at auction for a reasonable price (even if it isn't a true antique). I was told it is probably a twentieth century creation, and that seems consistent with a style that seems influenced by art nouveau or other modern western artistic movements. However, it does bear what appears to be a Qianlong mark.
Although my first assumption is that the mark is a fake, but want to be sure. I read somewhere on here that legitimate Qianlong marks are in blue, but I've read elsewhere that this is not a foolproof way to determine authenticity.
What do you seasoned collectors think?
This is a late 20th century product, in my view. The decoration and thickness of the enamels show clearly that it is from a later time. In addition to this, the base looks fairly new, with a dirty rim. A rim that is dirty like this one is almost always artificially made to look that way, because some buyers think that is a sign of age.
The Qianlong mark is apocryphal. Many items made during the 20th century show Qianlong marks, which never look like the the authentic Qianlong marks.