The first complete scientific study of Stonehenge's large stones has revealed some information about why their material resists damage due to weather. Researchers recently described a series of examinations that gave a look inside one of Stonehenge's 52 large stones, known as sarsens. The researchers studied a core sample taken from one of the sarsens, called Stone 58, during repair work in the 1950s. It was kept by its owner in the United States for many years before being returned to Britain for research in 2018. The examination gave information about Stone 58's inside structure. The sarsens are made of stone called silcrete. This silcrete is made of very small pieces of quartz held tightly together by quartz crystals. Quartz resists damage even when exposed to wind and weather. David Nash of the University of Brighton led the study that appeared in the journal PLoS ONE. Nash said the sarsen’s inside structure explains the stone's resistance to weathering and why it made an ideal material for monument-building.” In a remarkable act of engineering, the sarsens were put up in Wiltshire, England, around 2500 BC.