It's not Carnival glass, that is usually iridized. It's vintage, probably dates to the 1960's or 70's in my opinion. Not sure on the maker. could be Dugan, Westmoreland, Viking, Kanawha or a host of others. I don't think it's Northwood or Fenton, but I could be wrong. I was once, back in 1978 I believe it was, lol (joke). I'd call it a stretch glass vase with a diamond pattern and ruffled top. Color could be referred to as Colonial blue or Celeste blue. Some people may refer to it as a "swung vase" but the tops of those are usually more non uniform in shape. I can find a similar one but it offers no information- Blue Pressed Glass Vase - Imageck