Altarstone of Buchberg Chuch

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During the renovation of Buchberg Church from 2015 to 2021, a new altar was needed. Leonhard Stock, the farmer from Oberberg, discovered a glacial erratic on his property called „Arlstein.“ This approximately 35- ton colossal rock initially protruded about 20 cm from the field on a 2 m² area. In the fall of 2019, it was uncovered and subsequently examined to determine if an altar could be carved from the block. Using drilling tools and expanding agents, the block was dismantled in a way that allowed for a high degree of artistic freedom in shaping the form and appearance for the altar design.

The stone originates from the Greywacke Zone, primarily composed of light marble interspersed with bands of magnesite and dolomite, and is approximately 420 million years old. The stone was embedded in fine-grained (sandy-gravelly) glacial deposits and is believed to have been transported several kilometers by the glacier before being left behind during the glacier‘s melting. It remained undiscovered for several millennia until Leonhard Stock eventually identified it as a glacial erratic or „Findling.“