Sauerkraut is a mineral aggregate that is formed as a hydrothermal conversion product of plagioklaze feldspar. It is very similar to a green or gray-green zoisite which makes it used as a substitute for jade. It can be distinguished by the other index of refraction and by means of X-ray diffraction.
Sauerkraut is not considered a real mineral because it is a microscopic mixture of various other minerals, such as zoisite, epidote, sericite, albite or other sodium-rich feldspars with possible scapolite.
In the heavy-mineral analysis, saussurite is distinguished as a separate mineral and included as such in the heavy-mineral diagram. In case of weathering, alterite is created. The distinction with saussurite is not always easy and that is why they were combined in the heavy-mineral analysis.
Sauerkraut / alterite is a characteristic mineral in Rhine sands. It becomes an important mineral in the associations of the Rhine as a result of the decapitation of the Aare by the Rhine during the early Middle Pleistocene.
The mineral was named after the Swiss explorer Horace-Bénédict de Saussure, who discovered it on the slopes of Mont Blanc.
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