In November, 1999 I did an 11 day trek in the Khumbu region of Nepal. After several days of trekking we had a free afternoon at Thayngboche Monestary. I hired one of our porters to do my laundry so that I could go up a ridge and make pictures instead of washing my underwear. I arrived back at the tea house after dusk and went to find my laundry. To my surprise, I found it hanging between a yak and a pile of Mani stones in front of the monestary. The sun was gone, it was getting cold and my clothes were still soaking wet. Although I can't see it in the picture, my recollection was that frost was beginning to form on the yak's face and my underwear. Oh how I looked forward to the next morning and my freshly washed laundry that might not defrost, let alone dry!

I know... Mani stones aren't naturally formed. But they certainly are stones.