Faden Quartz (Gwindel?) – Val Cavrein, Grisons, Switzerland
 
Exceptional piece from the Val Cavrein in the Swiss canton of Grisons. The highly lustrous and water-clear crystal has a clearly visible thread (Faden) and is surrounded by other quartzes on a matrix. Apart from the good quality, it is special that the quartz shows a slight twist, which is otherwise only found in Gwindels. Scientists disagree on whether the combination of Faden Quartz and Gwindel exists, so the crystal cannot be clearly defined as Gwindel. Regardless, it is definitely a rare and unique piece.