Sarita Camacho at work

Turning sediments into art

Algarve biologist Sarita Camacho makes watercolours out of rocks and shells

An Algarve marine biologist and artist is enjoying success bringing both those worlds together to turn rocks and shells found in the region into unique watercolours. Praia da Luz in Lagos is one of her main ‘suppliers’ of materials.

The idea came to her in the midst of the pandemic, said Sarita Camacho, 46.

“Unwittingly whilst studying calligraphy, I started to learn about and became interested in the creation of pigments and paint. I took advantage of the lockdown and did my experiments. I collected rocks and sediments and started purchasing materials. I think this kind of activity is not very common in Portugal,” said Sarita, who has quite the unusual academic background.

Despite being a talented artist from an early age, Sarita decided to study Marine Biology at the University of Algarve (UAlg) after finishing secondary school and earned herself a PhD in 2013.

But the effects of the economic crisis at the time were still being felt and there were “no grants or projects” available, forcing her to find an alternative to biology.

“It had to be something I liked, found interesting and thought was necessary. I always liked and had a natural talent for drawing,” she said, explaining why she decided to pursue another degree, this time in Communication Design, which she completed in 2019.

With yet another academic achievement under her belt, Sarita started putting her talents and knowledge to work by creating illustrations, brochures and even characters for scientific projects.

“My clients are mostly universities which request scientific promotional works. They have asked for narratives, stories told by characters which I create through watercolour paintings,” she explained.

Her works have become more unique over time ever since she started using her own homemade watercolour paint, created with the sediments, rocks and shells she collects in the Algarve.

As Sarita already had experience processing sediments due to her background as a biologist, she quickly learned how to transform these materials into colours.

As she explained, “sedimentary rocks, which are formed out of other rocks that become fragmented and accumulate over time, creating new rocks, are ideal to make watercolour paint as they are much easier to fragment. As they form in different environmental conditions, many times they have different types of colours. And each colour represents a different historical period,” the artist-biologist said.

“In the Algarve, we have some cliffs where those different layers are visible to the naked eye,” she added.

Praia da Luz is singled out by the artist as an “exceptional place” with “beautiful cliffs with layers of colours that range from violet to mustard yellow, green, beige, pink and red”.

She added: “As the cliffs suffer the erosive effects of the environment, they break down and create rocks that are easy to access. There is no need to dig to obtain a sufficient amount.”

Schist (xisto) is also highlighted as an “interesting rock” that she uses thanks to the “greyer and pinker varieties which can be found in the Algarve”.

Even seashells are used by the artist to create colours – in this case the Anomia ephippium species, found commonly in the Algarve.

“There are two shades – yellow and pink. I have used both and tried to purify the colours as much as possible because they are not very pigmented. I was able to make a yellow and a pink shade. The result is a very tenuous pearly colour. If you look at the paper in the light, you can see the typical pearly shine of these shells,” Sarita said.

Along with her mother and daughter who also have their own artistic projects, Sarita has created a brand, ‘Tpot Design’, to market her watercolours. You can check their products on Facebook or they can be purchased online at

Orders started coming in almost as soon as the watercolours were put up for sale.

“We started the brand without the watercolours. We had some views but no sales. As soon as the watercolours went up, we started receiving orders from all over the world. We have already sold to many European countries, Australia and some cities in USA. I couldn’t believe what was happening. The palette with eight fluorescent colours was the best-seller, but the earth watercolours are also favourites. Here in our nearby community, I have sold many of the ‘Praia da Luz palettes’ to local artists or people who want them to give as a gift,” Sarita said.

According to the artist, being able to paint a beach or a landscape and use colours that were obtained from that very environment is “priceless”.

How are watercolours made from rocks and shells?
For those who are not well-versed in the realms of science or art, the process of turning rocks and shells into watercolours can seem too overwhelming to understand. However, Sarita walked us through the process.

“First, we collect the amount of the sample that we need and identify the rock, if possible. At home, at our studio or at the lab, we reduce the size of the rock.

If it is sedimentary, it is already free of impurities. If not, we have to process it first to remove any unwanted organic material,” she explained.

In a nutshell, the sample is collected, fragmented using a mortar and pestle and ground as thinly as possible.

A sieve is also used sometimes to ensure the grain is uniform.

“We weigh the amount of sediment we are going to use because the quantity of the other ingredients depends on the weight of the pigment. Finally, we bring everything together,” she said.

All paint has a binding element. In the case of Sarita’s watercolours, Arabic gum – a natural resin obtained from the acacia tree – is used to bring all the elements together. When it is sold in bulk, the gum comes in the shape of resin stones, which can then also be ground.

Added to the gum are distilled water, liquid glycerin and clove oil which acts as a fungicide.

Said the artistic biologist, “it is the mixture of these four ingredients which forms the binder. When we work with pigments of the earth, which are very different from each other and there is no exact chemical formula, what we do is normally start off with 50% of the pigment and 50% of the binder. At the end, we add the secret ingredient, Algarvian honey.”

“We test (throughout the process) and see how the pigment reacts. First, we make the mixture with a spatula and then use a glass pestle to work the pigment against another flat surface. The continuous friction makes the grains separate even more. Then we test the texture on paper to see the proportion of binder and pigment. Afterwards we fill the mixing palettes and wait a week or two and then refill them. Sometimes we have to repeat the process two to three times.”

Original article written by Maria Simiris for Barlavento newspaper.

Beautiful layered cliffs
Colours of nature
Colours range from violet to mustard yellow, green, beige, pink and red
Praia da Luz cliffs – a palette of colours
Rocks and sediments collected ‘locally’
Turning rocks and sediments into powder
Sarita Camacho at work
Sarita Camacho’s watercolour creations