Recent research has advanced the understanding of Stonehenge's Altar Stone, which has long puzzled archaeologists due to its distinct characteristics compared to the other bluestones and sarsens at the site. Initially thought to have come from Wales, like the smaller bluestones, chemical and geological analysis revealed that it likely originated from Scotland. Most researchers assumed the stone came from Orkney, a cultural hub in Neolithic times with documented connections to the Stonehenge builders. However, a recent study found that the stone's composition did not match that of Orkney's stone circles, ruling out this once-promising location.
Despite this setback, researchers, led by Professor Richard Bevins of Aberystwyth University, are optimistic about identifying the Altar Stone's origins. The analysis has narrowed down potential sources to the broader Orcadian Basin in northeastern Scotland, though it covers a vast area. By eliminating Orkney, scientists can focus their efforts on other parts of Scotland. While the exact location remains elusive, the mineralogical and chemical clues gathered so far provide a solid foundation for further investigation into this ancient mystery.