42mm x 22mm
This agate is the finest example of sagenitic agate I have yet found at St Cyrus. Interestingly, it is clearly only a section, highly weathered and water-worn, of a much larger stone, that by my estimation, must have been around quadruple the size when complete. I picked it up in April 2016, in an area where unusual agates occur infrequently amongst extensive beds of shingle and banks of sand.
It has been noted by other collectors, that Scottish sagenitic agates occur rarely, and generally without distinction. In my experience, this is true for the most part. Sagenitic agates are encountered at Ferryden and at Scurdie Ness, at Usan and at Lunan, but the best are found further north. These only occasionally reach the quality of their brethren at locations further south in Fife and in Perthshire. Tantalizingly, I have encountered very large sagenitic agates at Lunan and at Usan, but so far these have mainly comprised of examples so highly weathered that the pattern has been lost almost completely. There is one notable exception shown in the second page of Lunan galleries.