English Victorian pressed blue & white slag glass chalice/stemmed vase

Recently a new op shop has opened in my high street, what I would deem a "boutique" op shop as it is focused mainly on clothing & has all the stock carefully presented. I do prefer the old school op shops where things are shambolic & random, but they seem to be a dying breed...the new version is a touch too sanitised & curated for my taste. Probably because I literally grew up in op shops as my parents were not well off & most of our clothing & household goods were second hand. It was later that op shopping became a source of fun & "sport" for me rather than a necessity. Anyway, this new establishment does at least have a modest selection of bric - a - brac, & thus I found this fine example of English pressed glass from the Victorian era.
Made from blue & white slag glass, it measures 18.5 cm tall, 8.4 cm across the top rim, & 7.5 cm across the base.
It has a complex pressed pattern which complements the marbled blue & white colour & impressive chalice like form.
No markings but perhaps by Sowerby or one of the other classic English makers, circa 1870s - 1880s.