What is entailed for one who stoned the Jamarat with cement stones out of ignorance?

The majority of jurists stipulate that the throwing (of pebbles) must be done with stones, and throwing with cement is not permissible because it is not a stone. It is considered as if the throwing did not take place, and it is obligatory to slaughter a sacrifice (dam) in Mecca and distribute it to its poor. The Hanafis, however, permit throwing with anything that originates from the earth, so throwing with soil, clay, and gypsum is valid according to them. Based on their view, the thrower is not required to do anything, and his throwing is valid. However, the view of the majority of jurists is more sound.