The incident happened at around 8.40pm on Friday 4 December when the woman was walking with her dog through the park.
When close to the football changing rooms at the Quarry Lane entrance she was pulled to the floor and threatened with a bladed instrument by two males.
Several rings were then taken from her including her engagement ring (see pictures).
DC Dan Johnson of Leeds District Crime Team said:
“This was a particularly nasty attack against a lone female.
“The two attackers stole a number of items of jewellery including a ring with significant sentimental value.
“I would appeal to anyone who witnessed the incident, or anyone offered any of the items for sale to come forward.”
Officers want to speak to two males in connection with the incident.
The first male is described as white, around 5’10 tall and aged in his early 20s. He spoke with a local Leeds accent and had dark hair and brown eyebrows as well as dirty hands and nails.
He was wearing a hooded top, jogging bottoms tucked into his socks and dark Nike trainers. He also had a chain on which was either gold or silver that was curved.
The second male was also white and wearing jeans. He possibly had a fleck of ginger hair. He was possibly wearing a hat.
The full list of items of jewellery stolen is below
• An engagement ring which is platinum gold with a square diamond with diamonds around it.
• A silver thick tiffany band which curves out which is quite a large fitting with the tiffany script.
• A white gold ring with a light blue stone with small diamonds around it.
• A plain diamond white gold band.
Any witnesses or anyone with information is asked to contact DC Dan Johnson of Leeds District Crime Team on 0113 3859493 quoting crime reference 13200607514 or call 101.