Build like a Shell

The Ocean, the magma chamber, the Erlenmeyer flask of the scientist, the privileged space that marine organisms create to form their shells, the womb; all examples of contained fluids in which erratically moving elements are -often under manipulated circumstances- transformed into intricately ordered materials with unique properties: (bio)minerals; rocks, crystals, bones, external skeletons, shells, teeth.

Biominerals are formed at the cross-section of living and dead matter, an attempt of life to create order amid the random motions of elements in fluids and gasses, forming solid objects within and around the body, that remain preserved after death. Dissolution-reprecipitation reactions, occurring at the interface between liquid and solid, embody the idea that elements in our environment are rarely in a steady state, yet take part in an endless and delicate dance.

The human brain tends towards decreasing entropy; hence we create mental models of distinct features in our environment, such as the ocean, the atmosphere and the rock. Simultaneously, we are aware that elements are constantly moving between physical states, such as ice and water, and re-cycling in biogeochemical cycles.

For instance, in the rock cycle, sand grains and (bio)minerals precipitated from seawater settle down on the seafloor, are compacted and metamorphosed into rocks (used to build pyramids), uplifted to form mountains and eroded into sand grains (used to make concrete) and dissolved minerals, ultimately reaching the ocean again. These cycles, taking place at the nanometre-scale as well as spanning geological deep-time, are intertwined with the evolution of life, yet go beyond spatial and temporal scales of the human perception.

In the lab, I am growing my intuitions on precipitating (growing) minerals from solutions. Different polymorfs (shapes of crystals consisting of same elements, showing a different form/ crystal structure) emerge when changing the conditions of the solution: pH, temperature, presence of inhibitors and seeds.

I'm studying how crystals grow and dissolve into various shapes, as an analogy for many other systems in which shapes emerge and decay within an environment, such as bodies within the biosphere, thoughts and dreams within (interacting) minds and cities within ecosystems. Within these processes, I am interested in the role of entropy, allowing self-organization and attempts to exert (artistic) control from within these systems.

Above images: crystals grown out of breastmilk floating within a solution.

My amazing AMOLF colleague Marloes Bistervels grew these silica crystals in the Self-Organizing Matter lab. She choose to induce the growth of two crystals that would approach each other, and merge, to accompany some talks where we shared our love for mineral shapes appearing out of liquids.