The secret why the Stonehenge rocks last and never weather remains one of the mysteries of the ancient world. One of the most recognizable monuments that stood the test of time and connected to the dark times when man was inclined to superstition. 

One of the secrets of the stone's resistance to weathering lies in the composition of the rock, as one study suggests. This explains how the structure keeps standing intact for centuries.

Scientists took samples from one of the huge stone slabs, called sarsens, and analyzed them under a microscope. They were able to conclude that they are composed of a unique geochemical composition.

The Sarsens' Composition Revealed

The sample, named the Philip's Core, was extracted more than 60 years ago from today. It stayed as a souvenir in the US for decades, but was later returned to the UK two years ago, reported the Daily Mail.

Since extracted, the core was separated into six pieces. The smallest one was only 2.6 inches which were borrowed by the scientists to be analyzed in a study, noted UK Today News.

The sarsens composition revealed it was made of sand-sized quartz grains densely packed together by quartz crystals in between.

The unique chemical composition now exposes how Stonehenge stood for the last 5,000 years and defied the test of time. The sarsens were the perfect choice in making the structure to make it last for such a time.

The composition of Philip's core indicates the large stone sarsens were taken from 15 miles to the North, in the West Woods at the edge of Marlborough Downs, Wiltshire.

The researchers said that the results led to where the other stones were taken from the US to analyze other stones-looking for the secret of Stonehenge and its longevity.

Read Also: Archeologists Find 130 Homes Around German Stonehenge, Indicates That Ritualistic Site Was Once an Ancient Community

The research was led by Professor David Nash from Brighton University and other geoscientists together with other institutions to analyze the raw data from the sarsens.

Nash remarked that working on the project is a privilege, and the chance to do so is significant. He mentioned several institutions like the British Geological Survey and the Natural History Museum to analyze the core.

He added that the sarsen sample is the most studied stone than the moon rock itself.

What are Sarsens?

Sarsens are the stones that made up the Stonehenge and other stone circles in the Wiltshire village of Avebury.

Each stone weighs around 20 tons and is as tall as 7 meters. These stones are the 15 of the Henge's central horseshoe, also the uprights and lintels in the outer part of the structure. Outlying stones like the Heel, Slaughter, and Station stones.

The scientists were more interested in how the stones were formed before they were made into the famous Stonehenge in the Neolithic epoch.

Originally the sample was drilled from Stone 50 of Stonehenge by the British firm Van Moppes during 1958. The core's location was unknown until 2018 when Robert Phillips, of the Van Moppes, sent it back from Florida, cited News Zordo.

Robert Phillips was allowed to take the core after the drilling in is done. Nash said that the core might have been broken right after the drilling. As of date, the monument can no longer be drilled for samples as it has protected status accorded to it.

The secret of Stonehenge is the composition of densely packed material that kept it intact for a long time. Builders might have known of the characteristics of the stones for choosing them as the best material for the stone ring, was not an accident.

Related Article: Swarms of Summer Solstice Festivalgoers Converged on Stonehenge Despite the Cancellation of the Yearly Event