Stonehenge Altar Stone origin remains uncertain after new research
A study published in the Journal of the Geological Society found no matching rock source in northeast Scotland for the six-tonne stone.
Researchers have failed to identify the origin of the six-tonne Altar Stone at Stonehenge, according to a report by the Times of India. A study published in the Journal of the Geological Society on November 5, 2026, found no matching rock source in the northeast Scotland locations previously investigated.
The Altar Stone is a large slab of Old Red Sandstone, measuring approximately 4.9 metres long, which lies flat beneath the collapsed remains of the Great Trilithon at the Salisbury Plain monument in Wiltshire, England.
An August 2024 study in Nature had suggested the stone might have come from the Orcadian Basin in northeast Scotland after examining mineral grains like zircon, apatite and rutile. This would have meant the stone travelled more than 700 kilometres to reach the site.
An international team led by geologist Duncan Pirrie examined eight fragments of the stone and conducted non-invasive measurements on the monument. They compared these with 70 samples collected from Scottish rock outcrops, looking at chrome spinel, clay minerals and barium chemistry.
While mineral ages pointed towards an ancient source associated with the geological landmass Laurentia, none of the Scottish locations matched the complete geological characteristics of the Altar Stone. The findings make a northeast Scottish origin very unlikely.
The research has ruled out southern Britain as the source. Other possible locations for further investigation include other parts of Scotland, northern England and Ireland.