Natrolite – Zeolite  (Polished) - Hohentwiel, Hegau, Baden Württemberg, Germany
 Ex. Karl Rickauer Collection
 
 The white-yellow suns in phonolite rock from the type locality  Hohentwiel  are only accessible via old collections. Pieces of this size and such intense color are  very rare to find on the market.
 natrolite  is a hydrous silicate of the zeolite family. Named by Martin Heinrich Klapproth in 1803, the name is a composite of  natro (sodium bicarbonate)  and  litho  (Greek stone).