In an oyster shell

Through a material exploration of lime—one of the oldest known materials—it is revealed that limestone is formed by compressed seashells. This project highlights the importance of understanding our impact on the planet during the Anthropocene, through the story of one tiny humble oyster.

Expanded Project / MA Design: Expanded Practice
Goldsmiths, University of London

The story of lime, through shells as headphones

In an oyster shell is a project that aims to communicate the necessity of understanding human impact on the planet. It also aims to illustrate the interconnectedness of seemingly unrelated materials with certain processes. It does so through the design of an auditory experience that explores lime, one of the oldest known materials, which has a beautiful story to tell. A story that reflects the history of human civilisation.

Cycladic settlement, defined by the use of limewash

During the Anthropocene—the recent age of detrimental human impact on climate and the environment—people in so-called civilised societies are becoming increasingly disengaged with their surroundings. Consumerism and the convenient taking-for-granted of daily habits, foster this estrangement with the material world and with what ordinary products and the built environment are made of. Focusing on the importance of taking care of the environment, this project is metaphorically placed in the Cyclades—a complex of Greek islands in the Aegean Sea defined by the use of limewash in their vernacular architecture. It looks beyond the colour white, investigating the material, tracing it back to its very roots, to reveal how lime comes from limestone which is essentially compressed oyster shells.

I wanted to understand what lime is, where it comes from and whether it is just an architectural material used to paint white or make cement. After talks with chemists, people who work with raw materials and through my individual research, I discovered that most of it comes from limestone quarries in areas where sea shells have been compressed over hundreds of millions of years and have turned into stone, which is essentially calcium carbonate. So, I called an oyster bar in central London and got myself a crate of dirty oyster shells. I also went to Whitstable, in Kent and collected some more from a pile in front of the local oyster restaurant.

Pile of oyster shells in Whitstable, Kent

Crate of dirty oyster shells

When calcium carbonate (or an oyster shell) is fired at around 900°C, it releases CO2 and turns into calcium oxide, or quicklime. I fired the shells in a kiln and a day later I had my own quicklime. Quicklime is highly reactive, and once slaked with water it produces a lot of heat and forms calcium hydroxide, or slaked lime. Wanting to make my own slaked lime to complete the lime cycle, I simply added water to the fired shells. It didn’t work at first but after contacting the right people (thank you Steven), I found out that I had to add boiling water in order to speed up the exothermic reaction.

Oyster shells ready to be fired at 900°C

[GIF] Slaking quicklime: fired shells reacting with water

Wanting to make a tribute to the colour white of the islands, I “vandalised” Goldsmiths and painted a brick white using my very own limewash. This brick, made in a factory somewhere, by some people, out of various materials, all coming from different places, is now white, using fired oyster shells collected from Whitstable and elsewhere, by a Greek person wanting to make a tribute to some Greek islands architecture. It highlights this interconnectedness of materials, activities and processes.

When my lime dried I made a silicon mould and mixed some of the lime powder with plaster, to make an oyster shell, out of oyster shells.

Limestone, CaCO2 → Quicklime, CaO → Slaked lime, Ca(OH)2

Different forms of slaked lime are used in various stages in all kinds of industrial activities, such as the purification of sugar, glass making, paper making, toothpaste etc. Limescale formed in the sink or in a kettle, is also a form of lime. We are literally drinking oyster shells. Wanting to communicate what I had found, I decided that a layout of the material in its different forms seemed too obvious. There needed to be a way for people to really feel the materiality of lime.

When you cover your ear with an oyster shell, you can hear the ocean. I wanted to use that very motion to show how much more you can hear; how much more lies beneath the surface of an ordinary material such as lime; how much more is connected with oysters than one would think. As mentioned above, lime is all around us in all kinds of industrial processes and everyday activities. To reveal that, I decided to design an auditory experience that replicates this motion of listening to an oyster on the beach, by triggering the hearing sense. I hid a speaker inside the plinth and connected it to the shells via a PVC tube with a 3mm diameter. Sound travels inside the tube, making the shells act as headphones.

The audio file I created is 90 seconds long, and consists of six, 15-second long sound clips. You can hear the eating of an oyster, blasts in a limestone quarry, quicklime reacting with water, brushing teeth, sounds of paper and running water form a tap. Lime is present in all these sounds in one way or another. Here is a 30-second version of the audio file:

Expanded Publication

Expanded Publication (Dissertation) / MA Design: Expanded Practice
Download inanoystershell.pdf