The ground lip.Again you could see the mold seams.
I paid 50 bucks for this guy and have really enjoyed it for a few years now.
The only true cobalt MASON PAT jar I have seen,was a Consolidated jar,and went for over ten grand.
The only known original cobalt CFJCo is actually a Mason's Improved jar rather than the Mason's Patent 1858 variation. It did indeed sell for well over $10,000. It can be seen in the middle of Darrell Plank's amazing shelf of blue jars at www.darrellplank.com.
The blue 1858 that was dug a few years back was somewhat lighter blue, that is, medium cobalt. It is a quart with no monogram but with a large Hemingray style mold number 3 on the base. It also sold for $10,000 or more. The current owner brought it to the Muncie jar show earlier this month. He was still working up the courage to have the jar cleaned. It supposedly came from a later dump and could have been pitched as late as the 1950's. Folks in the 19th Century had little reason to throw out good useable jars.
I don't recall a good blue CFJ blue midget on Ebay. If you dig up the photo, I'd like to see it. These midgets do exist in a deep cornflower or light cobalt. Here is another Darrell Plank link for his blue midget CFJ reverse. http://www.darrellplank.com/jars/Pics/blumidgt.jpg