St Cyrus III
On this page I have included some photos of more unusual specimens from the St Cyrus area. These include 3 examples of finely marked tube agates with the light inclusions resembling writhing aquatic worms or undersea foliage swooning in an incoming tide. Also included is an unusually finely marked sagenitic agate. Pseudomorphs occur infrequently in Scotland, but at St Cyrus and also at Usan, coloured and detailed examples can be found, sometimes in large sizes. One such pseudomorph is shown on the bottom far left. For those uninitiated, pseudomorphs are crystalline nodules of various varieties of minerals where after the formation of the aforementioned crystals, agate has later formed within cavities. This later influx of silica can leave unexpected and intricate patterns of agate within a nodule. Various species of inclusions in pseudomorphs associated with many varieties of mineral are known as zeolites. It is unknown to me at present which mineral(s) formed the basis of the aforementioned agate. These stones are difficult to spot, appearing like nodules of quartz or calcite, although generally due to their water worn nature they will exhibit some fortification banding on their skins when wet. Suspected examples are best dipped in the convenient surf to determine their persuasion.