This is a beautiful Caithness glass paperweight named "Ascension", designed by Alastair Macintosh and dating to the last quarter of the 20th century. 
The paperweight has a cone, egg shaped form, having colours including blue swirl with orange net to the centre and medium bubble and smaller controlled bubbles, making a very distinctive design.
The Caithness Glass Company began making paperweights circa 1962 Paul Ysart,Colin Terriss,Alistair Macintosh,Margot Thomson Inns Burn where some of Caithness makers designers of Caithness glass paperweights.
The makers mark is etched to the base with CAITHNESS ASCENSION SCOTLAND and a scratched edition number alongside as per the images.
This paperweight weighs about 500 gram.
Caithness glass
The company was founded in 1961 by Robin Sinclair and initially only made bowls, vases and drinking glasses. After Paul Ysart joined the company a year later, that paved the weigh for Paperweight production, with regular factory production starting in the late 1960s.
In 1974 the first millefiori and lampwork paperweights were produced leading to various designers producing many specially designed paperweights.
Over the next two decades, Caithness saw a substantial change, the company going into receivership in the early 2000's, when the company was purchased by Dartington Crystal (Torrington) Ltd in 2006.
 
Diameter
2.75 in
Height
3.5 in