The Messenger of Allah said: "The Black Stone descended from the Paradise, and it was more white than milk, then it was blackened by the sins of the children of Adam."  

قَالَ رَسُولُ اللَّهِ ﷺ نَزَلَ الْحَجَرُ الأَسْوَدُ مِنَ الْجَنَّةِ وَهُوَ أَشَدُّ بَيَاضًا مِنَ اللَّبَنِ فَسَوَّدَتْهُ خَطَايَا بَنِي آدَمَ قَالَ وَفِي الْبَابِ عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو وَأَبِي هُرَيْرَةَ  

He heard the Messenger of Allah saying: "Indeed the Corner and the Maqam are two corundums from the corundum of Paradise. Allah removed their lights, and if their lights had not been removed then they would illuminate what is between east and the west."  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ إِنَّ الرُّكْنَ وَالْمَقَامَ يَاقُوتَتَانِ مِنْ يَاقُوتِ الْجَنَّةِ طَمَسَ اللَّهُ نُورَهُمَا وَلَوْ لَمْ يَطْمِسْ نُورَهُمَا لأَضَاءَتَا مَا بَيْنَ الْمَشْرِقِ وَالْمَغْرِبِ