The 58-year-old Duchess married her Prince in 1986, in a ceremony watched by millions.
To celebrate their engagement Prince Andrew bestowed Fergie with a stunning Burmese ruby and diamond engagement ring.
It was similar in style to Sarah’s close friend Princess Diana’s.
Sadly, the marriage was not to last and the couple split.
Andrew and Sarah announced their separation in 1992 and legally divorced four years later.
However, Sarah continued to wear the red jewel long after this.
In fact, Fergie last wore the ring in public in 6 September 2000, four years after their legal divorce and eight years after their separation.
The occasion was Princess Beatrice’s first day St George’s School.
Sarah’s ring was visible as she was seen hugging her young daughter.
Prior to this Sarah was spotted wearing the ring on 7 December 1995.
In their engagement interview Prince Andrew told the media: “We came to the mutual conclusion that red was probably the best colour for Sarah.
“That’s how we came to the choice of the ruby.
“The extra bits around the outside, we wanted something that was slightly unconventional.”
How much is Sarah Ferguson’s engagement ring worth?
The ring was created by Garrard, which also created Diana’s engagement ring.
While the total cost of the ring is not known it can be assumed the price tag was rather hefty thanks to the costly centre stone.
According to Hello! the Burmese ruby chosen by Andrew to represent Fergie’s red hair cost him a whopping £25,000.
Given inflation, the same stone would cost £71,350 today.
You won’t believe how much Princess Diana’s engagement ring is worth now.