As there is no pic, I had to go and look it up.

I found a large amethyst beast, pretty much in the shape I would normally describe as a being a volumetric flask, but I used to work in labs (and yes, I've
used Monax).
So I am presuming you have a Monart piece in this shape. Like the Gullaskruf bottles - a big round base, with a very tall slim neck?
But you also say "The" Berluze vase. This confuses me because my brother has one, so if it's the shape I'm thinking of, yours isn't the only one.
But I'd love to know the colourway of yours!
My brother's is ambery yellows and I think there's a touch of blue going on around the middle of the base and some very fine goldy aventurine.