The incredible preservation of this Dead Sea scroll-the inevitable destruction-may be salt.

The Temple Scroll is one of the longest and best-preserved scrolls in the Dead Sea. It is made of 19 pieces of leather, and its surface is covered with inorganic salts and mineral layers. The dark mottled area (the central area in the figure) indicates the position where the inorganic layer is separated from the bottom. In a new study, researchers try to find out what this inorganic layer is made of. Israel Museum, Jerusalem)

The Dead Sea scroll is a miracle. In a series of caves in the Jewish desert, piles of rubble and bat dung were buried for about 2 years, and nearly 1 fragments of manuscripts were collected, including Bible texts, ancient calendars and early astronomical observations.

among these mysterious handicrafts (many of which are now just tattered pieces of parchment), the well-preserved documents attract people's attention. The temple scroll, named after a Jewish temple that has never been built, is one of the longest (up to 25 feet, or 8 meters), thinnest and easiest to read.

Why, among thousands of faded fragments found in Jewish caves, did the Temple Scroll perform so well after two thousand years? In a new study published today (September 5) in the journal Science Progress, researchers tried to find this by carefully examining a piece of parchment with every X-ray and spectral tool they could use. They found that this scroll did have something that its ancient brothers did not have-there was no trace of salt mineral solution on the scroll studied before, nor was it in any cave or the Dead Sea itself.

Related: Dead Sea Scroll Gallery: A glimpse of the past

According to researchers, the existence of these minerals shows that the Dead Sea scrolls were made with impressive technologies, and more importantly, this discovery may also provide information for the future preservation of these scrolls.

"Understanding the characteristics of these minerals is particularly important for developing appropriate protection methods to preserve these precious historical documents. The researchers wrote in the research report:

Previous studies have shown that the Temple Scroll is different from most other dead sea fragments, and it consists of several different layers: an organic layer consisting of animal skin as a parchment base; An inorganic mineral layer that may be rubbed during the "finishing" of parchment. Although all Dead Sea scrolls can be attributed to animal skins-usually taken from cattle, goats or sheep, then scraped and stretched on a shelf-there is little evidence that they have been completed, the researchers wrote. The research team studied

what this inorganic layer is made of and whether it was rubbed there on purpose. The research team studied the temple scroll fragments using X-ray scanning and Raman spectroscopy-a technique to reveal the chemical composition of substances by observing how lasers scatter various chemical elements. They found that the scroll was covered with a mixture of salts made of sulfur, sodium, calcium and other elements. However, these salts do not match the elements found naturally at the bottom of the cave or in the Dead Sea, which excludes natural sources.

The author concludes that the temple scroll must be completed in an unusual way, which has never been used in other known Dead Sea scrolls. The research team wrote that this salt coating may be one of the reasons why the temple scrolls were well preserved, but at the same time, it may also be one of the reasons why the scrolls were eventually destroyed. According to the author, because the salts detected on the reel will absorb water from the air, if stored improperly, their existence will "accelerate the degradation of the reel". Twenty-four amazing archaeological discoveries, 3 of the world's most valuable treasures are still missing, and 25 of the most mysterious archaeological discoveries on earth < P > were first published in the journal Life Science.