The agate-finding location Dunbog is very famous for its well formed “sagenitic agate” (pseudomorphous after zeolithes). One of this agates is on the frontpage of Dr.H.G.Macphersons book “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