KUTNAHORITE on ARAGONITE

The Kutnahorite is a double carbonate of calcium and manganese, whose chemical formula is the following: CaMn (CO3) 2
It named after the town of Kutna Hora, Czech Republic, where it was discovered for the first time, in a silver mine (which I personally visited), in the form of coatings of dark matrix dolomite.

In Italy it was found for the first time about 40 years ago (1970), in a town in the province of Arezzo.
I was one of the first to discover, in a plowed field, in which the farmer with the plow had broken some geodes, gleaming in the sunlight.

Brought the Institute of Mineralogy, University of Florence, turned Kutnahorite or Kutnohorite (the colored sides, in the form of spherules or aggregates) of aragonite (the shiny needles) all within a body rather hard clay, in the form of geode.

Even the Aragonite is a carbonate, calcium, whose formula is: CaCO3
Belonging to the same family of minerals justifies the simultaneous presence of two elements.

The area of discovery, a few million years ago, was subject to volcanic phenomena, overheated water, saturated with minerals, cooling, originated these geodes, which thus dating roughly from 1.5 to 2.5 millions of years.

The Kutnahorite occurs through different colors, from almost transparent, to yellow, to red / brown to black, while the aragonite is always transparent and shiny, fragile and (attention) pointed !
The two substances are not soluble in water, so the geodes can be washed, gently; They are soluble in aggressive acids (hydrochloric, sulfuric, etc ...), in which melt causing effervescence.

The location within which they are located has the size of about 100 m to 50 m, is planted with vines, olive trees and, with annual rotation, artichokes, sunflowers, alfalfa, etc ... It is a clayey soil, thus subject a significant change, depending on the moisture present: from "soft / sticky" to "dry / tough, almost like rock."

Geodes are loose in the ground, up to a few meters deep and come to the surface through the runoff of rain and human labor (plowing).

It is a phenomenon unique, researched and documented by the "International Mineralogic Review," a top American scientific authorities, as well as by all the major Italian magazines and mineralogical associations.

The charm of these objects uniqueness stems from the rarity of the specimens and the perfection of the crystals, which transmit all their beauty if well-lit and maybe magnified.