I presume, based on the modern looking sticker on your decanter, that this is a modern piece. It is a nice example of cut glass and is lead glass or "lead crystal"
Even if it were antique, there is not a great market for clear decanters right now. I recently sold a very nice 19th century example with its correct stopper for $30 and was happy to get that price.
Here is a link to lead glass...
https://en.wikipedia.org/wiki/Lead_glass
