The Altar Stone at Stonehenge in Wiltshire, UK, is enigmatic in that it differs markedly from the other bluestones. It is a grey–green, micaceous sandstone and has been considered to be derived from the Old Red Sandstone sequences of South Wales. Previous studies, however, have been based on presumed derived fragments (debitage) that have been identified visually as coming from the Altar Stone. Portable X-ray fluorescence (pXRF) analyses were conducted on these fragments (ex situ) as well as on the Altar Stone (in situ). Light elements (Z<37) in the Altar Stone analyses, performed after a night of heavy rain, were affected by surface and pore water that attenuate low energy X-rays, however the dry analyses of debitage fragments produced data for a full suite of elements. High Z elements, including Zr, Nb, Sr, Pb, Th and U, all occupy the same compositional space in the Altar Stone and debitage fragments, and are statistically indistinguishable, indicating the fragments are derived from the Altar Stone. Barium compares very closely between the debitage and Altar Stone, with differences being related to variable baryte distribution in the Altar Stone, limited accessibility of its surface for analysis, and probably to surface weathering.

A notable feature of the Altar Stone sandstone is the presence of baryte (up to 0.8 modal%), manifest as relatively high Ba in both the debitage and the Altar Stone. These high Ba contents are in marked contrast with those in a small set of Old Red Sandstone field samples, analysed alongside the Altar Stone and debitage fragments, raising the possibility that the Altar Stone may not have been sourced from the Old Red Sandstone sequences of Wales. This high Ba ‘fingerprint’, related to the presence of baryte, may provide a rapid test using pXRF in the search for the source of the Stonehenge Altar Stone.

Sourced from the Tyrrhenian Islands and exchanged over long distances, obsidian was used widely across prehistoric Western Europe. An obsidian core and bladelets from a newly discovered rockshelter site in south-eastern Spain, however, raised the possibility of an unrecognised mainland source of obsidian. EDXRF analysis of the Early Magdalenian finds from La Boja links them to a source 125km to the south-west. The artefacts were discarded during two brief activity phases at the site, indicating that obsidian procurement was integral to the technological choices of the site's users. The specificities of the technocomplex may explain the unique nature of this occurrence.

Zhokhov Island in the Siberian High Arctic has yielded evidence for some of the most remote prehistoric human occupation in the world, as well as the oldest-known dog-sled technology. Obsidian artefacts found on Zhokhov have been provenanced using XRF analysis to allow comparison with known sources of obsidian from north-eastern Siberia. The results indicate that the obsidian was sourced from Lake Krasnoe—approximately 1500km distant—and arrived on Zhokhov Island c. 8000 BP. The archaeological data from Zhokhov therefore indicate a super-long-distance Mesolithic exchange network.

The long-distance transport of the Stonehenge bluestones from the Mynydd Preseli area of north Pembrokeshire was first proposed by geologist H.H. Thomas in 1923. For over 80 years, his work on the provenancing of the Stonehenge bluestones from locations in Mynydd Preseli in south Wales has been accepted at face value. New analytical techniques, alongside transmitted and reflected light microscopy, have recently prompted renewed scrutiny of Thomas's work. While respectable for its time, the results of these new analyses, combined with a thorough checking of the archived samples consulted by Thomas, reveal that key locations long believed to be sources for the Stonehenge bluestones can be discounted in favour of newly identified locations at Craig-Rhos-y-felin and Carn Goedog.

The authors present a new procedure for discovering where stone artefacts come from without having to cut a slice through them. The method is tested on axes of spotted dolerite bluestone from Preseli in Wales, source of monoliths at Stonehenge.