The most northerly parts of the British Isles, lying more than one hundred miles from the northeast tip of the mainland, are the Shetland Islands. Accessed by a frequently turbulent ferry crossing or short plane journey this is also the northernmost location of agates in Britain. The range in Scotland therefore stretches from the Cheviot Hills in the south to the Norwegian Sea, a distance of more than three hundred and fifty miles.

On the western coast of mainland Shetland, rocks of Old Red Sandstone age can be found on the Esha Ness peninsula. These consist mainly of a series of andesitic lavas, tuffs, agglomerates and ignimbrites.

Agates can be found near Stenness and it is said that stones with blue, grey and white colouring can be found occasionally with a touch of white and pink. In my experience having visited Esha Ness the stones were small red and white but of variable quality. However some locals have amassed large collections of good quality stones.