These jars are called "petal jars" by collectors.  I have no idea where the term came from or whether this is what they were originally called.  The name comes from the "petals" on the shoulder of the jar.  These are available in aqua but they also come in this deep forest green on occasion and much more rarely in cobalt blue.  Collectors would love to see one in amber.  There is one that is kind of olive amber but there is no known out and out amber petal jar.

This particular example is a pretty standard quart version in green.  These are rare enough and pretty enough to bring a substantial value in sales.  They are very early jars and like so many of them, have iron pontils on the base and are unlabelled.