Via Scientific American:
“The surface of the earth is far more beautiful and far more intricate than any lifeless world. Our planet is graced by life and one quality that sets life apart is it’s complexity.”
Carl Sagan in “Cosmos – The Persistence of Memory“
In July 1791 the French aristocrat, adventurer and naturalist Diedonnè-Silvain-Guy-Tancrede de Gvalet de Dolomieu published a short article describing a peculiar limestone he had observed during a voyage in the Alps. The white rock was very similar to common limestone, but the mineral grains forming the unusual rock showed almost no reaction with acids, unlike crystals of calcite or aragonite (the main minerals of limestone), which react violently. Three years later the naturalist Richard Kirman introduced the Dolomite as a new mineral; the name from there became used to name the dolostone rocks and finally gave the Dolomites – referred in the past simply as the “Pale Mountains” – their actual name...
For many years scientists have been investigating how the carbonate mineral dolomite is formed but no concrete results have ever emerged... until now. Researchers in Germany, Spain and Switzerland have succeeded in shedding light on this puzzle, finding that bacteria play a key role in this mineral's formation. The results are presented in the journal Geology.
Led by the Cluster of Excellence 'The Future Ocean' and GEOMAR |Helmholtz Centre for Ocean Research Kiel in Germany, the team examined globally distributed marine bacteria that use sulphur compounds instead of oxygen to generate energy (i.e. sulphate respiration). They discovered that primary dolomite crystals are formed under conditions that are currently found in marine sediments.