Where is the Princess of Wales' engagement ring? It's been a question on royal fans' lips over the past few weeks, ever since she was spotted without it for her video announcing she had completed her preventative chemotherapy treatment.
For her latest outing at Southport with her husband Prince William, Kate once again kept the mystery of the missing engagement ring alive by sporting four sparkling bands – none of which were the sapphire previously owned by Princess Diana.
The Princess teamed her Welsh gold wedding ring with her Annoushka eternity band thought to be given to her by William following Prince George's birth. Both make regular appearances on her left hand, but they were joined by two new additions.
One was the sapphire and diamond eternity band she debuted to congratulate Team GB in August, and another was a new eternity ring.
While it's not clear where the latter came from, some have mused that the former could be a more practical, day-to-day alternative to Kate's iconic engagement ring since it features the same stones.
Diana originally chose the Garrard ring because it reminded her of her mother's engagement ring and the sapphire matched her eyes. Continuing the blue theme, Kate even coordinated the ring with her Issa dress for her engagement photocall.
She has rarely been spotted without the heirloom from Diana in her thirteen-year marriage, aside from some hospital visits for health and safety reasons.
Kate's ring challenges
Health could also be the reason the royal has swapped her engagement ring. Oncology pharmacist Dazhi Liu previously told HELLO! that chemotherapy could have an impact on her jewellery choices.
"During cancer treatment, there are several practical reasons why someone might need to take off their rings," said Dazhi. "Chemotherapy can cause fluid retention in the hands, which might make rings tight and difficult."
Meanwhile, Ben Roberts, Managing Director of Clogau – the brand responsible for the Welsh gold of British royal wedding rings – told HELLO! that the upkeep of Princess Kate's ring would come with it's "challenges."
"Most people don’t know the level of upkeep that wearing an heirloom day-to-day can entail," began Ben. "Even without any alterations, caring for an heirloom of such value comes with its own challenges.
"Kate and her team will need to employ careful maintenance, with regular inspections and in-depth evaluations, gentle cleaning to restore sheen, and, if necessary, expert repairs to ensure its longevity.
"That way, she can continue to wear it every day and maintain a constant connection to the past while grounding her in the present as a beloved senior member of the Royal Family."
LOOK: Meghan Markle's sentimental diamond engagement ring designed by Prince Harry: all the details