103mm x 61mm
Agates with smoky quartz or purple amethyst centres (always in my experience with the coloured quartz being surrounded by clear quartz) occur in the St Cyrus area infrequently. Yet, there are far fewer nodules of a purely quartz persuasion to be found here, as opposed to the Scurdie Ness or Usan areas. Scurdie Ness is a particular scourge to those who disdain quartz in agates in any form.
Anyway, this very large nodule was discovered by myself close to where a large stream meets the shingle beach during the autumn of 2015. I have found a handful of very large pieces in the same area in the last year or so. All incorporate clear quartz into their make-up, and most in what I personally consider attractive formations. Witness the rare colour along the nodule's edges (presumably influenced by the lightly coloured fibrous inclusions) These inclusions are also to be found in the generally diminutive orange-pink agate nodules originating from the same general area. I believe they may be calcite.
Another aspect of this agate geode worth noting is the incorporation of the small area of brown andesitic rock at its base. In all agates of over 10cm in diameter I have from the area this andesitic rock is found still attached. This probably derives from the nature of the weathering. The stone being dislodged in layers, with the largest pieces clinging most successfully (presumably due to weight and size) to the rock.
When I cut the stone (the half's mate is incomplete but slightly glorious regardless) I had been almost immediately elated but quickly decided it was too fractured to have polished. I disagree now and consider it a fine choice despite the damage. It has poise.