OK an update on this vase - having fairly recently acquired a Dartington amber 'Candy Vase' (with sticker) I was able to compare this black vase with the 'Candy Vase' - the base finishes are identical as are the lip dimensions and general finish, plus the size of this vase is exactly what it should be if it were a Dartington 'Inkwell' vase. Now having re-read Mark Hill's book (page 55 of 'Frank Thrower & Dartington Glass') which states that Frank Thrower was the designer (Kim designed the box - I got my facts wrong in my initial posting) it says that these vases (made in 1978-79) were reputedly outsourced to Wood Brothers in Barnsley because Dartington were unable to produce them in the colours they wanted.
I am fairly certain now that this is indeed a Dartington 'Inkwell' vase from the same range as the Volterra and Candy Vases but it's a very unusual colour for Dartington (black - purpley when looked though a light source) . We know that these were made in amber, sage green and grey glass - and now, perhaps, purpley black - can anyone shed any light on this?
If possible, please could a moderator alter the heading of this thread to include 'Dartington Inkwell Vase' in the title?