Sun letter Uncommon

One of fourteen Arabic letters that cause the "L" of a preceding definite article اَل‎ (al-) to be assimilated in pronunciation. The sun letter suppresses the sound of the "L" and then geminates: al + ṣīn = aṣ-ṣīn. The effect of the sun letter is limited to pronunciation and does not affect the spelling, except that a shadda may be written over the sun letter and in the fully vocalised spelling lām lacks any diacritics: الصِّين‎ (aṣ-ṣīn). The fourteen sun letters are ت‎ (t), ث‎ (ṯ), د‎ (d), ذ‎ (ḏ), ر‎ (r), ز‎ (z), س‎ (s), ش‎ (š), ص‎ (ṣ), ض‎ (ḍ), ط‎ (ṭ), ظ‎ (ẓ), ل‎ (l), ن‎ (n). Phonetically, they represent coronal consonants.