Oxford is almost as far away from the sea as you can get.

But Ingrid Thomas, who has made the city her home for the past 40 years, has spent 20 of those years avidly collecting sea shells, and for most of them, she hasn’t moved from her house in pursuit of her interest.

To start with, she travelled across the world in search of them and could be seen, barefoot on the beaches of far flung countries and islands, gathering shells wherever she could find them.

She sent them home to the UK, later to identify them and store them in her studio. She was always very careful to abide by local regulations concerning the collection of shells, and only added sustainable specimens to her growing hoard.

Shell collecting became a passion, and Ingrid realised she was drawn not only to the beauty of the shells themselves, but also needed to find out more about how they live in their natural habitat, conservation concerns, and importantly how shells have had an impact on humankind throughout history.

While she carried on adding to her mounting collection, Ingrid embarked on her research, and after several years, she became one of the country’s foremost experts in the field. To her delight, she was commissioned to write the definitive book The Shell: A World of Decoration and Ornament, published in the UK, USA and overseas, containing over 400 colour illustrations of shells in all branches of the arts.

Coming from an artistic family herself, and with her own keen eye, Ingrid also decided to share her passion with others, and created framed studies using actual shells for people to hang on their walls and permanently enjoy their beauty. She successfully exhibited these works in Artweeks for a number of years.

“What I loved most was the reaction of so many people to the amazing colours, shapes, textures and patterns of these natural objects, and the harmony they could generate when framed in different styles and moods,” she recalls.

Now in her seventies, Ingrid has decided to close this chapter of her life, and in the New Year, will embark on a new career as a speaker. She will be giving talks to children and adults, telling the many fabulous stories about how shells live, and entertaining her audiences with the many surprising ways in which we have used them in our daily lives.

Meanwhile, Ingrid’s cornucopia of glorious shells has been stored in jars, boxes, drawers and cupboards of her studio, and she has now decided to sell the majority of this unique treasure trove so that others can enjoy them.

She will hold a sale in her Oxford home, where people will be welcome to come and select their own favourites from a dazzling variety of tropical beauties, and at very reasonable prices.

“I’m not unhappy to say goodbye to these shells,” she says. “I’ve been the guardian of many of Nature’s greatest gifts, and it’s time that they move on to different homes where they’ll be admired and appreciated by their new owners.”

Half the proceeds of the sale will be donated to 4Oceans, a charity that is working to clear the seas and coastlines of plastic waste.

Ingrid Thomas’s shell sale

Saturday 27 - Sunday 28 October, from 10am to 4pm, at 11 Bainton Road, Oxford OX2 7AF.