Very attractive and the two pix show the colour change from bright lavender in daylight and incandescent light, to steely blue under fluorescent (tube) lighting.
If you go to David's glassyEye.com page and run down to dichroic glass - you should get some info plus David's link to the very informative site from Judith Van Buskirk-Gugudan.
Caithness offered these cut floral vases, designed in 1987, at the time of their acquisition of the King's Lynn Crystal factory, and according to Mark Hill's book (Caithness Glass - Loch, Heather & Peat) aspects of design came from both factories - they also did a clear cased blue. The book shows a cut vase from this range (page 98), in neodymium, but different shape, which he refers to as 'lavender', but no mention in his book that I can find of dichroic glass - believe they did p/w's in neodymium.
Can't see lavender in the colour swatches in Mark Hill's book, so not sure how the factory referred to this colour. perhaps is was their heather - anyone know how commonly or otherwise neodymium was from Caithness?
Height is about 8" (205 mm).