It does appear to be Chinese. There's a website you can visit for pottery markings and the ones from China have four small symbols set in a single square as your ginger jar shows. They have a lot of various symbols and could not tell if any were your jar's markings. Just do a search for pottery markings and you can see them from various countries. This is the one I saw it from: www.bing.com/
You can ask on this website:
Sadly, in most of of the ones I have seen, the answer is that it is 20th or 21st century, sold at Pier One Imports or the like.
Still, it is nice to have it validated by an expert!
Post back what you learn!
Here is a site that you can check out to find your mark. I looked and some of the images on the site are hard to read but I think I saw one or two that would match the mark on yours. I think it is best to make sure it is right. gotheborg.com/