Kleberesten

Kleberesten, also known as Kleber shards or Kleber fragments, are a type of rare and valuable mineral specimen primarily associated with the mineral kleberite. Kleberite itself is a complex phosphate mineral with the chemical formula Na₃Ca₃(PO₄)₃·H₂O, first identified in the late 19th century. The term "Kleberesten" originates from German, where "Kleber" means "glue" or "adhesive," and "Reste" means "remnants" or "residues," though the exact etymology in this context is less clear.

These fragments are typically found in small, irregularly shaped pieces, often embedded in rock formations or as loose specimens. Kleberesten are notable for their translucent to transparent appearance and a range of colors, including white, yellow, pink, and pale green. They are often associated with other phosphate minerals and are commonly found in pegmatite veins, which are coarse-grained igneous rocks formed from slowly crystallizing magma.

The rarity of kleberite and its fragments makes Kleberesten highly sought after by mineral collectors. They are primarily sourced from a few known locations, including pegmatite deposits in Brazil, Russia, and Namibia. Due to their scarcity, these specimens can command high prices in the mineral market, particularly when they are well-formed or exhibit vibrant colors.

Beyond their aesthetic and collector value, Kleberesten hold scientific interest due to their unique mineral composition and the geological processes that lead to their formation. They are often studied to better understand phosphate mineralization and the conditions under which such minerals crystallize in pegmatitic environments.