Gwindel

The highly sought-after Gwindel are twisted quartz crystals which, according to the Mineral Encyclopaedia of Switzerland, can be described but still not explained. Surprisingly, gwindel growth can occur in the midst of simultaneously grown normally shaped quartz crystals.

A distinction is made between open, closed and semi-closed gwindels. Open gwindels are clearly more common, closed ones correspondingly rarer and even more popular with collectors. Even small gwindels can cost several hundred francs, larger ones, depending on quality, intactness, lustre, etc., several thousand, if not tens of thousands of francs.

Photo: Quartz (smoky quartz nappy), Piz Giuv GR, Felix Spahr collection; not for sale.