Discussions have taken place regarding the exact cause of the material’s flexibility. At one time it was ascribed to the presence of thin scales of mica which were believed to permit a certain amount of motion between adjacent grains of
quartz. More probably, however, it is due to the porous character of the rock together with the interlocking junctions between the individual quartz
sand grains. The porosity allows interstitial movement, while the hinge-like joints by which the particles are connected hold them together in spite of the displacement. These features are dependent to some extent on weathering, as the original rock matrix contained constituents which were later removed, leaving open cavities in their place, while at the same time additional
silica may have been deposited on the quartz grains, interlocking their irregular surfaces more perfectly together. Most of the known itacolumite specimens are also fine-grained. In some cases, they are said to lose their flexibility after being dried for some time, probably because of the hardening of the interstitial substance, but many specimens kept in a dry atmosphere for years retain this property to a high degree. ==References==