Very large antique STUART ? vase 6kg 12” tall C1900 unsigned

“English Stuart Crystal Vase………...Price: $2500.00. ………..Antique English Stuart Crystal Vase C. 1900
For the serious collector. As good as it gets in English crystal. In mint condition.”
This is how I have seen one advertised. I would love some help to find provenance for this vase. The base is huge polished pontil with two deep scribed circles and wear suitable for antique vase. The lip of the vase is about 1” thick with very deep cut sculpting intaglio flower and leaf work. It is a very heavy vase weight 6kg and height 12”. I wonder if it is flint glass. It is very bright and beautiful.