The incident happened at around 4pm on Wednesday, August 10. when a 44-year-old woman was walking on a footpath between Moor Lane and Summerdale with a dog when she was approached by a man.
He demanded money and attacked the victim with a stone.
Officers want to speak to man described as wearing all black clothing and a black baseball cap with his face covered.
DC Roberts of Kirklees CID said; “This was quite clearly a terrifying incident for the victim and it is very fortunate she was not seriously injured.
“I would appeal to anyone who was in and around the area near to Moor Lane, either walking, jogging or driving who may have seen someone matching the suspect’s description, or who may have seen or heard anything suspicious to come forward.
“Our enquiries are ongoing to trace the person responsible. ”
Any witnesses are asked to contact DC Roberts Kirklees CID on 101 quoting crime reference number 13160344357.
Information can also be passed to Crimestoppers anonymously on 0800 555 111.