Adularia (rare ''Faden'' group) (ex Obodda)

Item Description

There are many European Alpine localities that are well known for producing superb Adularia specimens, but there are a few "Alpine-type" localities in the high mountains of Pakistan that produce some great specimens in their own right. Adularia is a low-temperature variety of K Feldspar and is most commonly associated with metamorphic deposits such as those in the Alps. This specimen hosts several razor-sharp, highly lustrous, GEMMY, white/colorless, somewhat blocky crystals of Adularia in a beautiful "Faden" growth. "Faden" is the German word for string, and the term is most often applied to Epidote or Quartz specimens with a distinctive growth line through the specimen. The following information paraphrases the listing for Faden Quartz from mindat.org, but it also applies to Adularia in this case:  "Faden minerals form in fissures in the host rock that widen slowly and steadily. While the fissure continues to open steadily, the crystal will also continue to crack and heal. Because growth is much quicker on fractured surfaces than on regular faces and because it leads to small regular faces on the opposite conchoidal fracture surfaces that do not perfectly match, some of the growth solution is included in the crystal. The repeated rupturing and healing leaves a scar of liquid and gas inclusions in the crystal: a white thread, the "faden" ". A very showy and fine quality "Faden" Adularia from this famous locale in Pakistan. Aside from Switzerland, Pakistan is the only locality that I can think of which produces these unusual Feldspars. From the Herb Obodda dealer stock.