“Turritella agate” is a very popular gem stone in the USA. The naming is somewhat problematic, since the Turitellidae are seawater tower snails, and the snails in the so called “Turritella agate” live in the fresh water. The snails are belonging to the kind Elimia. These fossils are approximately 50 million years old. The suitability as gem stone depends substantially on the degree of the silification. A stone with high content of chalcedony receives a good polish and gives interesting insights to the inside of the snail housings. Often small diskus-like flea cancer (Amphipoda) housings in large number are there situated.