Do we know where the stone from Newgrange was quarried ?

Fozzydog3 wrote: »

When I was at the Newgrange "Museum" there was a section that said that the rock was carried over from Wicklow, I'm wondering, have any potential quarry sites been found yet ?

No, not yet.
The usual theory is that that the quartz came from Wicklow, the greywacke from Clogher Head, and the remainder from the Mournes.
None of this has been proven, as far as I know.
The greatest challenge in locating quarries, is how to identify them as working sites, and what evidence remains.

Not everyone is convinced that the bluestone came from Preseli.
Mike Parker Pearson's work at Craig Rhosyfelin was seriously challenged in 2015.

Abstract
The Afon Brynberian valley is claimed to contain Britain’s most important Neolithic quarry, used for the extraction of bluestone orthostats destined for Stonehenge. Archaeologists argue that an exposed rock face within a meltwater channel at Craig Rhosyfelin is a quarried surface, and that an eight-tonne block found five metres away was prepared for transport but then abandoned. Site
investigations have revealed scoured surfaces, faceted and abraded erratic boulders, glacial till, fluvioglacial sands and gravels, and widespread rockfall and solifluction deposits. All the features associated with the “proto-orthostat” are considered to be natural. There are currently no visible prehistoric landforms or sediments that are demonstrably anthropogenic in origin.

Brian John, Dyfed Elis-Gruffydd, and John Downes (2015) Quaternary at Craig Rhosyfelin, Pembrokeshire. Quaternary Newsletter.


It is very difficult to prove absolutely that stone x came from bedrock in place y, especially when the investigator is looking for evidence that the stone was worked in prehistory and attempting to tie that evidence to the appearance of similar stones in a monument.
It is a useful principle in archaeology to not depend on morphology alone.
MPP examined more than 1200 stone 'chips' recovered from the centre of Stonehenge. These consisted of spotted dolerite, rhyolite, and 'rhyolite with fabric'. The chips were analysed in thin section in 2011 and compared to samples deposited at the Preseli site. The result was 'A strong petrographic match...'.
But most of MPP's conclusions were drawn from the morphology of the bedrock and dislodged stone surrounding it. He concluded that a 4m long monolith was deliberately detached from the parent rock and was subsequently manoeuvred into a position where it could be worked. It may have been. It may also have become detached naturally and deposited naturally in this position. It was concluded that the monolith was deliberately positioned on supporting stones, but this may very well have been a consequence of the way it was excavated.

As far as I am aware, no such analysis has been undertaken in regard to the Newgrange petrology. Part of the reason for this is probably because the Newgrange stone types (quartz, greywacke, and granite) could derive from many different bedrock sources on the island.
To prove that the stone was quarried from a specific location, it would have to be demonstrated that there was evidence to show how the rock was exploited in tandem with reliable thin section analysis of the petrology.
That would be a major challenge because the stone types are common and petrological identification down to a specific or unique source would be extremely difficult.
Recognising the source (if there was one) on the basis of evidence from working the stone would be highly unlikely. 5000 years of weathering could obliterate any signs of stone extraction. MPP himself admitted that there was no definite evidence to show how the stone was exploited at Preseli (yours truly had a long discussion with him on this subject). His best guess was that fissures in the bedrock were opened up with wooden wedges. If that was the case in Neolithic quarrying, then it would leave no visible evidence. I have serious doubts about the effectiveness of wooden wedges in cleaving rock. The theory is that dried wedges were hammered into position and then wetted to cause swelling. My own research (2014) has proven that this would not produce sufficient force to cleave even the most friable bedrock. There are alternatives such as fire-setting, which is well documented from the Bronze Age mines of the southwest of Ireland. This leaves durable and clear evidence but was not seen at Preseli.