An extremely rare specimen of amber-colored calcite from Rüssingen, associated with an unidentified blue mineral. The specimen is composed of exceptionally well-crystallized, sharply terminated calcite crystals, forming a unique and highly aesthetic intergrowth. Specimens of this quality and crystallization are exceptionally rare for this locality, making this a truly unique and outstanding example. The contrast between the warm amber calcite and the blue mineral adds strong visual appeal and further emphasizes the uniqueness of the piece. A one-of-a-kind specimen of high collector significance from a very uncommon association.