An unfinished ‘butterfly’ slab from Structure Seventeen?
Over the past 17 years, excavation at the Ness of Brodgar has revealed hundreds of examples of Neolithic “art”.
These vary from light, ephemeral markings to deeply, and precisely, inscribed decoration. There’s no doubt the latter were meant to be seen – at least for a while – but what about the former?
Although there could be numerous less-practical reasons, it may be that some were “sketches” – designs that later had pigment applied, or perhaps scratched into existing “painted” surfaces. Alternatively, some may have represented the preliminary stages of more elaborate decoration.
That may be the case for one stone slab revealed this summer.
The stone, incorporated into the outside of Structure Seventeen’s inner wall – one of the two buildings underlying Structure Eight – featured a beautifully executed, and deeply incised, “Brodgar Butterfly” design.
On the same face were other lightly inscribed decorations – including bands, crosses and triangles.
While we will never know for sure, it seems possible that at least one of these was laying out a design for further embellishment.
As you will see from the photographs, the work to cut a motif to the right of the “butterfly” followed the “sketch marks” but was not completed.
Look closely at the completed “butterfly” and you can see what are either the guide marks for its execution or later decorative embellishments.
Was this intended to be another decorated slab? One which was abandoned after work began?
Unfortunately we will never know for sure but it is interesting to note that one of the finest incised slabs found to date was recovered from the same stretch of wall, a few metres to the south-west.
The question is, however, were these designs incised during the construction of Structure Seventeen or added when Structure Eight, or other later buildings, imposed on top. If the latter, then the designs would have been covered by masonry.
This raises an interesting point. While some decorated stones were clearly meant to be seen, it seems that others were not – and there are numerous examples of the latter across the site .
As Dr Antonia Thomas noted, the decorated stones visible during the structures’ use tended to be extensively incised all along their edges – the result of multiple episodes of carving.
The hidden stones – particularly those in walls – had single motifs that were the result of one carving session.
“It is difficult to explain such a pattern if the presence of the hidden stones were due to simple re-use,” wrote Dr Thomas, adding that the “placement of these stones, and the concealment of their carvings, was considered and significant.” 
-  Thomas A. (2020) Art in context: the decorated stone assemblage. In Card, N., Edmonds, M. and Mitchell, A. (eds) The Ness of Brodgar: As it Stands. The Orcadian: Kirkwall.
-  Thomas, A., (2016). Art and architecture in Neolithic Orkney: process, temporality and context)