Answered by Shaykh Abdurrahman ibn Yusuf Mangera
A concerned sister was asking if there is any such thing as a stone or rock (with ayat or surahs in it) that can detect whether someone has been affected by a jinn. Her brother believes that he was and wants to buy it — he was told that the rock would burn if touched by a person who was indeed affected by a jinn (the intensity marking how much he has been affected).
Assalamu alaykum
In the name of Allah,, the Beneficent the Most Merciful
We do not know of any such rock or where it can be purchased. It is possible that certain individuals who have the knowledge of this art may possess such stones or they may be just ordinary stones upon which they have recited something.
These practices are best left to those who possess knowledge of the art, and every person is not to venture in to this field. Likewise, a person who acts strangely is not always possessed. I have heard many scholars state that the majority of such cases are merely from depression and other psychological tensions and have nothing to do with jinns.
And Allah knows best.
Wassalam
Abdurrahman Ibn Yusuf