This jar is a little bit outside of my normal collecting interests which are crude pre-1900 beautiful jars.  Outside of the color, it's not crude nor particularly beautiful as an unembossed machine made jar.  Still, it's a very interesting jar.

Safety Valve jars are very common in aqua.  They occasionally come in green.  There is a version with a greek key design around the edge that I think is very pretty.  However, prior to this jar, the green ones have only been known in pt, qt and hg.  This is the first half pint known.  That, of course, makes it a very interesting jar.

The other surprising thing is that this was found in an antique shop here in Washington.  Washington is an antique challenged state.  The hotspot for rare jars is in the midwest and there isn't a lot of rare jars left for poor Washington state so to find one like this is a rare event.  I'm aware of an amber midget which came from Concrete, WA and there are some apple green Suns which have turned up in the Tacoma area but these discoveries are few and far between.