Finding a Luqatah but being ignorant of the ruling

Q: I was in the Kingdom of Saudi Arabia in 1398 A.H. With my seven-year-old son, who found a small gold chain that was worth 100 Riyals at the time. As I had wanted to buy one, I took it, because I was ignorant of the ruling on Luqatah (a lost item found by someone else). I now want to give its value away as Sadaqah (voluntary charity). Should I give an amount equal to its value at the time I found it or its current value? Please give us a Fatwa (legal opinion issued by a qualified Muslim scholar) and may Allah reward you with the best. As-salamu ‘alaykum warahmatullah wabarakatuh (May Allah's Peace, Mercy, and Blessings be upon you!)

A: If the situation is as you mentioned and you do not know who the owner of the chain is, you should give its current value away as Sadaqah. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.