(An-Naba') 78 : 20
وَسُيِّرَتِ الْجِبَالُ فَكَانَتْ سَرَابًا
And the mountains will be moved; then they will become just like a mirage.
It is told in verse 101: 5 that on that Day the mountains will become like carded wool. See explanation 24: 39; 27: 88; and 7: 10.