A rock bearing Yoko Ono’s handwriting has been stolen from the Gardiner Museum, Toronto police say. The theft reportedly occurred around 5:30 p.m. on March 12.

The rock is part of an art exhibit featuring Ono, where patrons can meditate using several river rocks. The stone is inscribed with black ink, and reads “love yourself” in block letters. It is valued at $17,500 (U.S.), Toronto police media officer Gary Long told the Star Friday evening.

“It’s a totally interactive (exhibit), there’s a bunch of rocks on the ground and people can walk up to them and pick them up,” Long said. The intention is that the rocks are returned to the exhibit once the meditation is over.

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“She just picked it up and walked away with it.”

The woman is wanted in a theft over $5,000 investigation, police say. Anyone with information is asked to call 416-808-5200.

She is described as 55-60 years of age, and standing approximately 5’4”. She was wearing a black coat, red scarf with black stripes, black pants, black hat and black shoes.