Description: The detail of the upper handhold part of the amphibolit stone cutter with the layer of incrusting solids. The grains of quartz sand which were stuck in the petrified substance at the time when the layer was made up by the pulp, soft and originally organic compound are clearly visible. They were the remains of the colagen subcutaneous ligaments and fat scraped off the wrong side of the fur during the proces of tanning. The stone tools which were extensively stained by such slimy substance fell into mud in which lacking the air the proces of petrification took place in the following millenia. The result is the present-day discovery of numerous this way stained stone tools used in far distant past for processing of the fur.