This is a half gallon amber snowflake or "tudor rose".  I grew up with the term "snowflake" but "tudor rose" seems to have become more popular in recent years.  The term describes (or at least, is supposed to describe) the rather odd little design on the back of these mason jars.  Nobody is sure why it's there or what it means.  Jerry McCann has championed the "Tudor Rose" name and theory.  He claims that this is an ancient design representing the God of grain I believe (demeter?).  That's as good an explanation as any I think but again, nobody's really sure.

I've known about amber snowflakes (reverting to my old habits) since I was a kid.  There are only a handful and I remember a friend of mine getting one in Kansas City and I thought it was the most amazing thing I'd ever heard of.  I think that's a lot of what caused me to be excited about this jar.

One of the most interesting things about the snowflake jars (which also come in clear, aqua and ball blue) is the disk immerser cap.  If you look just under the cap in the picture you can see an odd looking "upside down mushroom" hanging from the cap inside the jar.  That's the immerser.  The idea was that when you sealed the jar the immerser would push down any fruit floating on top and keep them below the syrup line so they didn't dry out and come out all ooky ("ooky" isn't really jar lingo, but seems to fit here).

When I was a starving college student, my roommate told me one day that he'd just spoken to a fellow about my collecting habit and the fellow had told him to let me know that he had an "amber snowflake".  I didn't figure this to be very likely and accused my roommate of trying to pull one over but, as he pointed out, he had no idea what an "amber snowflake" was.  To make a long story short, yes the guy did have an amber snowflake and I got it cheaply at the time but it was still more money than I could afford in my position so I only bought it knowing that I could sell it for more which I did.  It's still around though - recognizable by a tiny crack on the shoulder.  I'm not sure who owns it now but I hear about it once in a great while.