Dūrre-i bayḍāʾ (the white pearl) is the Aql-i Awwal (First Intellect). (Iṣṭilāḥ, 537)
Dūrre-i bayḍāʾ is the First Intellect (Aql-i Awwal) because of the hadith meaning "The first thing Allah created was the dūrre-i bayḍāʾ" (Le'āli, 1, 20) and the hadith meaning "The first thing Allah created was the intellect" (Aclūnī, I, 263). (Kāshānī, 44; Jāmiʿ, 83)
(See also: aql-i awwal; yāqūt-i ḥamrāʾ / yāqūt-i aḥmar)