> Which ancient monument is made of two types of stones, known as sarsen stones,and bluestones?And the answer: Stonehenge. Stonehenge is an enormous prehistoric monument in England, believed to have beenconstructed between 2000 and 3000 BC. The monument uses two types of stones: thelarge vertical stones are made of sarsen, a type of sandstone, and the smallerstones are known as bluestones, named as such because they appear to have abluish tint when wet.Efforts to identify the source of this ancient monument have been long pursued,but nearly all have ended without success. Up until last summer, archaeologistsbased their knowledge of the sarsen stones on some 400-year old calculationsmade by William Lambarde, a 16th century antiquarian. His accounts source thesarsens to the highest points of the Marlborough Downs, some 18 miles north ofStonehenge, yet Lambarde apparently came to such a conclusion based on theshared appearance of the rocks alone. David Nash, a geomorphologist at theUniversity of Brighton, has since been working with rock samples and geologicaltracing technology to seek the truth about the sarsen rocks. According to newfindings, Nash was able to pinpoint their exact source in the West Woods, 15miles away. As technology evolves, so too does our ability to identify essential informationabout this mysterious crop of rocks. While early knowledge came from folkloreaccounts dating back thousands of years, modern advancements in geochemicalscience have created ample opportunity to reconsider what we hold to be trueabout Stonehenge. Sourcing the rocks is just the first step in putting togethera full picture of this sacred site. Did you know?The monument's stones are known as "ringing rocks". When struck they produce aloud clanging sound, a fact which likely explains why someone bothered totransport the bluestones over such a long distance (some 200 miles!) In certainancient cultures, such rocks are believed to contain healing powers. To read more about Nash's recent and past findings, read the New York Timesarticle here[https://www.nytimes.com/2020/07/29/science/stonehenge-archaeology-sarsens.html]. Or, check out this[https://www.smithsonianmag.com/history/new-light-on-stonehenge-11706891/] National Geographic article for more information.