The "hellish" origin of the famous gemstone

(NLDO) - A team of German and Australian scientists has discovered the mysterious origin of a gemstone they call "fire-forged ice".

According to Science Alert , the gemstone that scientists are trying to learn about is sapphire, which has a sparkling blue color, cold like ice.

But authors from Heidelberg University (Germany) and Curtin University (Australia) discovered they have extremely hot origins.

A rough sapphire gemstone excavated from the Volcanic Eifel - Photo: Sebastian Schmidt

For many years, sapphires have been found in volcanic deposits such as Volcanic Eifel, where magma from the Earth's mantle rises into the crust over long periods of time, creating molten deposits rich in sodium and potassium.

Others are found in river beds as crystals.

But volcanoes only serve as carriers of gems. Exactly where they are forged remains a mystery.

In the new study, scientists considered two hypotheses: Did they form in the mantle itself, or were they molten from other minerals as magma rose?

They collected 223 micro-sapphires from the Volcanic Eife mine and performed secondary ion mass spectrometry, which revealed the rutile and zircon impurities trapped in the sapphires as they formed, the oxygen isotope ratios in the alumina, and several other factors.

It is the very things that make up a stone that tell its history.

The results showed that the source of sapphire must be the Earth's deep crust rather than the mantle, which is closer to us than previously thought: just about 7 km below the surface.

However, the thing that plays an important role in forging it is "hell".

Some sapphires are created from mantle magma melting rock as it moves through, changing the composition of the Earth's crust and forging the gemstone.

Other types of sapphires form when the molten material permeates the surrounding rock, triggering sapphire formation through heat, resulting in gems with isotopic ratios more typical of mantle origin.

It is this harsh process and the mysterious color of sapphire that leads authors to call it "ice forged in fire."

The study was recently published in the scientific journal Contributions to Mineralogy and Petrology.

Source: https://nld.com.vn/bang-trong-lua-nguon-goc-dia-nguc-cua-loai-da-quy-noi-tieng-196240819105824206.htm