The oversized ring has a square aquamarine jewel perched on a silver band.
The choice of jewel could have an important meaning, 77 Diamonds managing director Tobias Kormind stated.
Speaking exclusively to Express.co.uk, he said: “These images depicting the nonchalant, empowering glamour of a handsomely sized cocktail ring hold particular allure at the moment, reminding us of times when we can get dressed up and feel special.
“The meaningful, century-old symbolism behind these gems also brings a sense of hope for the future.”
Sophie is not the only royal to sport such a jewel and Princess Diana notably had a similar piece. The Princess of Wales wore the ring on her engagement finger following her divorce from Prince Charles.
The expert added: “Princess Diana wore a 24-carat aquamarine gem, worth about £30,000 to £40,000 due to its provenance. Our bespoke service would be able to create this same design by sourcing a similar aquamarine gem for around £18,000.”
The oversized gem was part of her private collection and was most recently spotted on Meghan Markle.
The Duchess of Sussex displayed the bold jewel as she headed to the reception on her wedding day in 2018.
It is likely to have been gifted by Prince Harry and it also features an oversized jewel on a silver band.
Aquamarines jewels are in a bold blue colour and are believed to represent things such as “serenity and calm”, Tobias continued.
“Aquamarine has a mesmerising light blue colour that is very similar to the ocean. This is the reason for its Latin name ‘aquamarina’, meaning ‘water of the sea’,” he stated.
“These gems are known to be symbols of prestige, strength but also serenity and calm.
“The most sought after aquamarines have an intense ocean-blue colour and are completely clear of internal marks or inclusions.”
Sophie has worn her ring on various occasions and, like the ring previously owned by Princess Diana, it could be worth a small fortune.
Tobias stated: “Countess Sophie’s ring is about 20-carat, and should be worth around £16,000.
“Her ring seems to be set with two side gemstones, in a trilogy design.”