• خَرْدَل

Appears 2 times in the Quran.

1. 21:47 وَنَضَعُ ٱلْمَوَٰزِينَ ٱلْقِسْطَ لِيَوْمِ ٱلْقِيَٰمَةِ فَلَا تُظْلَمُ نَفْسٌ شَيْـًٔا وَإِن كَانَ مِثْقَالَ حَبَّةٍ مِّنْ خَرْدَلٍ أَتَيْنَا بِهَا وَكَفَىٰ بِنَا حَٰسِبِينَ

   And We will set up a just balance on the day of resurrection, so no soul shall be dealt with unjustly in the least; and though there be the weight of a grain of mustard seed, (yet) will We bring it, and sufficient are We to take account.
   

2. 31:16 يَٰبُنَىَّ إِنَّهَآ إِن تَكُ مِثْقَالَ حَبَّةٍ مِّنْ خَرْدَلٍ فَتَكُن فِى صَخْرَةٍ أَوْ فِى ٱلسَّمَٰوَٰتِ أَوْ فِى ٱلْأَرْضِ يَأْتِ بِهَا ٱللَّهُ إِنَّ ٱللَّهَ لَطِيفٌ خَبِيرٌ

   O my son! surely if it is the very weight of the grain of a mustard-seed, even though it is in (the heart of) rock, or (high above) in the heaven or (deep down) in the earth, Allah will bring it (to light); surely Allah is Knower of subtleties, Aware;