ITACOLUMITE, THE WORLD’S MOST BENDABLE ROCK

This naturally occurring, rare, and unusual rock is named for a mountain range in the southern part of Minas Geras, Brazil, which is a region famously known for being very rich in quartz and other minerals (Wikipedia, 2023).

Itacolumite (pronounced “ita-col-um-nite”) is only found in a few places in the world; for example, Brazil, Charkhi Dadri District, Harynana, northern-central India, North Carolina, and Georgia. At the Indian locality, itacolumite is exposed in small quarries and occurs in a nearly 3 m-thick that is non-flexible bed, traceable over several tens of meters in length. The bendable sandstones, however, occur only in thin slabs extracted from this bed (Kumar and others, 2019). 

Thin short slabs (hand-specimen size) of this so-called “magical rock” will bend due to their own weight. If turned over, each slab will bend in the opposite direction. If a slabs bend too much, it will break.

                          A

                          B

                                    C

Three views of a slab of itacolumite [8.5 inches (24 cm) long, 1.5 inches (3.75 cm) wide, and just over 1.2 inches (1.5 cm) in thickness].   

A. Side view of slab bent downward. B. Top view. C. Close-up view of the slab. This rock, which is pinkish red with gray-colored zones (boundaries diffuse), consists of medium-grained feldspathic quartz sandstone. Locality unknown.

Small pieces of this rock are pricey! For example, the slab shown above, goes for $200! 

                          D

                          E

                                 F

Three views of a second slab of itacolumite [6 inches (15 cm) long, 1.5 inches (nearly 4 cm) wide, and about ¼ inches (7 mm) in thickness]. D. Side view This slab, which is grayish yellow in color [typical for itacolumite], consists of fine-grained muscovite-rich quartz sandstone. Locality unknown.

Itacolumitre is porous and consists of quartz-rich sandstone. The porosity (void spaces), which enables the bending process, is apparently caused by chemical corrosion (leaching) of feldspar grains in the rock (Kumar and others, 2019). Fine-grained muscovite mica can also present, but its presence has been determined not to be a factor in the bending process.

Note: Several short, interesting videos are available on Youtube.com that show the bending of slabs of this rock. 

 Sources of Information: 

Kumar, P. and others. 2019. Itacolumite (flexible sandstone) from Kalinana, Charki Dadri Districth, Haryana, India. Journal of Geological Society of India 93:278-284. Pdf is free.

Youtube.com/watch?v=ALHkg-11Lkk

Wikipedia. 2023