The “blue Hole” is a legendary agate-finding location in Usan. This hole was mined by a few scottish agate-collectors in the 19th century. The precisely position of this location is unknown today. Some of the finest scottish agates are originated in that place. The nodules reached a size up to 12 cm in diameter. The agates are coloured in a great diversity of colours. Beside the common bluish-white and fine banded ones deeply red colored specimen could be found. Some others are showing pastels in pinkish or yellowish. “Onyx-agate” (“water-level-agate”) is quiet often part of the pattern of these beautiful agates. “ Eye-agates” are rare.
The National Museums of Scotland are owner of two collections of fine agates from this locations (Robert Miln collection and Matthew Forster Heddle collection). Specimen from these collections are the highlights of the public presentation of scottish agates.
More informations about scottish agates are given in Dr.H.G. Macpherson´s book “agates” (published by the British Museum (Natural History) and the National Museums of Scotland).
You can find more informations about scottish agates on the following webpages:
Chris Harlows webpage about scottish agates
Nick Crawfords webpage scotsagate
H.Currie Minerals of Scotland