vedenkostein

Vedenkostein is a rare and distinctive mineral that belongs to the group of hydrated calcium sulfates. Its name derives from the Finnish words *veden* (water) and *kostea* (moist), reflecting its hydrated nature. The mineral was first identified in the early 20th century in Finland, where it was found in evaporite deposits, particularly in the context of old salt mines and brine pools.

Vedenkostein has a chemical composition of CaSO₄·2H₂O, similar to bassanite but with a slightly different crystal structure. It forms as a white, translucent, or slightly yellowish powder or crystalline mass, often appearing in fibrous or acicular habits. The mineral is relatively soft, with a Mohs hardness of around 2 to 2.5, and is soluble in water, which contributes to its occurrence in hydrated environments.

Occurrences of vedenkostein are limited, primarily documented in Finland and a few other regions with similar geological conditions, such as salt deposits and evaporitic settings. It is typically found alongside other sulfate minerals like gypsum (CaSO₄·2H₂O) and anhydrite (CaSO₄). Due to its rarity and specific formation conditions, vedenkostein is not commonly encountered in mineral collections or commercial applications.

From a scientific perspective, vedenkostein serves as an important example of hydrated sulfate minerals, offering insights into the crystallization processes in evaporitic environments. Its study helps geologists understand the formation and evolution of salt deposits, as well as the behavior of water-bound minerals under varying temperature and pressure conditions. While not widely recognized outside specialized mineralogical circles, its unique properties continue to be of interest in geological research.