The famous "Helix Aqua" owned for generations by the family of Professor Doctor Hermann Bank of the famous Idar-Oberstein family of gemcutters: This piece was the best piece in his collection, and was the cover of his private book (1981). It has never before been seen in a professional photo in its recently cleaned state of existence... It was left dirty and unprepped for nearly 80 years since he brought it out of Brazil in the 1930s and saved it from being cut in the lapidary center of the world at the time. It was a privilege to be the one to get to win the trust of the last owner, and prepare and sell the piece on commission. The piece is simply fantastic and holding it in your hands leaves you staring at its internal complexity, mesmerized. It masses 7 kilos of the finest classic of seafoam blue aquamarine color with unusual and unique helical phantoms dancing inside. It now resides in a place of honor in the Perot Museum of Nature and Science in Dallas, TX, on loan from a private investor. The stone is considered to be one of the world's greatest gem crystals.