Jarosite Identified as a Natural Geological Clock for Mars Exploration.

Science and Technology

In May 2025, Indian researchers explored Jarosite, a rare iron-potassium sulfate mineral found in the arid Kachchh region of Gujarat, and confirmed its potential as a natural geological clock for Mars exploration.


      - Jarosite typically forms in acidic and saline environments and is linked with acid mine drainage, oxidized ore deposits, and glacial or clay-rich terrains.

      - Jarosite is a yellow-brown hydrous sulfate mineral with the chemical formula KFe₃(SOâ‚„)â‚‚(OH)₆. It is composed of potassium (K), ferric iron (Fe), and sulfate (SOâ‚„).

      - It has a trigonal crystal structure, hardness of 2.5 to 3.5 on the Mohs scale, thermal stability up to 450°C, and forms through the oxidation of iron sulfides like pyrite. It serves as the iron analogue of alunite.

Main Point :-   (i) Six jarosite vein samples were collected from the Kachchh region and examined in a lab to assess their luminescence properties. Luminescence is the light emitted by minerals when they release energy stored from natural radiation over time, helping track geological changes.

      (ii) The study revealed that jarosite grains saturated with radiation doses ranging from 590 to 2,600 gray, showcasing their capacity to accurately record geological events—a key trait for developing natural timekeeping systems for planetary surfaces like Mars.

(iii) Jarosite has previously been discovered on Mars by NASA’s rovers Spirit, Opportunity, and Curiosity, indicating the presence of acidic and oxidizing conditions in Mars' past.

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