Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
quran:105:4

Striking them with stones of hard clay,  

pelting them with stones of baked clay,
القرآن:١٠٥:٤

تَرْمِيهِمْ بِحِجَارَةٍ مِنْ سِجِّيلٍ  

{ترميهم بحجارة من سجيل} طين مطبوخ.