Some very basic points ...
The problem with glass items made in China but having a Murano label has been known for many years and there has a been much said about what had been happening, both outside and within Murano.
However, the term "fake" is too generalised to cover all the options, and is probably best left unsaid if there is no documentary proof of what is being claimed. It may be another matter for early 20th century "copies" of some weights from USA.
But it is widely known that paperweights (and probably bowls, vases, etc.) which have been made iin China have been found in shops on Murano (and elsewhere). One of the options to consider is that an item may be made in one country but have some "finishing" done in another country and therefore a "made in <wherever>" label could be ok - even if it upsets local makers.
But that is a complicated subject, so back to the basics ...
As Allan (paperweights) has said, the item here is definitely of Chinese origin.
It is not only the base finish which can help to Id this type of weight. All of the internal elements; birds, animals, lily-style flowers, and the way they are formed and presented can be found in a varietry of colours and with and without a mix of elements, in thousands and thousands of weights.
Weights of this type have been made for a long time. I have some Chinese catalogues from the year 2000 which show a large range of weights, some basic millefiori and some with creatures and flowers etc etc. Very similar items are still made today. And the output is gradually getting more and more refined.
And the bases of many of the more recent examples are smooth polished.
A basic search on this Board for "Leonardo paperweight" and "Royal Crest paperweight" will bring up some discussions on fairly recent import items.
There are lots of other modern import companies in lots of countries selling lots of this type of weight. Search the internet for "Chinese import paperweight" for a range of offerings.