Story at a glance
- Researchers used CT-scanning, X-rays, microscopic analysis and other techniques.
- They discovered the stones are made up of sand-sized quartz grains that are cemented tightly together by an interlocking “mosaic” of quartz crystals.
- Researchers said that’s what makes the stones so “impervious to crumbling or erosion.”
New research is shedding light on how the Stonehenge monument in southern England has remained standing since it was erected roughly 5,000 years ago.
Researchers from the University of Brighton conducted the first comprehensive analysis of samples taken directly from one of Stonehenge’s megaliths to reveal the geological and chemical structure of the stone.
During a restoration program at Stonehenge in the 1950s, a stonecutter named Robert Phillips managed to retrieve a cylindrical core sample of one of the stones measuring about 3 feet long. Phillips brought the souvenir back with him to the U.S. and was in possession of it for several decades until he provided the material for research in 2018, just a few years before he passed away in 2020.
“It is extremely rare as a scientist you get the chance to work on samples of such national and international importance,” professor David Nash, a co-author of the study, said in a statement.
“Stonehenge is part of a World Heritage Site and is subject to the strictest legal protections, so it would be highly unlikely that we would be able to access this type of material today. Getting access to the core drilled from Stone 58 was very much the Holy Grail for our research,” Nash said.
The core sample didn’t disappoint.
Researchers used CT-scanning, X-rays, microscopic analysis and other techniques and discovered that the sarsens, the massive boulders that make up the monument, are composed of sand-sized quartz grains that are cemented tightly together by an interlocking “mosaic” of quartz crystals.
Researchers said that’s what makes the stones so “impervious to crumbling or erosion.”
“This small sample is probably the most analyzed piece of stone other than Moon rock,” Nash said.
The findings were published in PloS ONE.
Stonehenge is one of the world’s most famous prehistoric monuments and was built in multiple stages over several thousand years.
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