SB 10.56.3

śrī-śuka uvāca
āsīt satrājitaḥ sūryo
 bhaktasya paramaḥ sakhā
prītas tasmai maṇiṁ prādāt
 sa ca tuṣṭaḥ syamantakam
Synonyms: 
śrī-śukaḥ uvāca — Śukadeva Gosvāmī said; āsīt — was; satrājitaḥ — of Satrājit; sūryaḥ — the sun-god; bhaktasya — who was his devotee; paramaḥ — the best; sakhā — well-wishing friend; prītaḥ — affectionate; tasmai — to him; maṇim — the jewel; prādāt — gave; saḥ — he; ca — and; tuṣṭaḥ — satisfied; syamantakam — named Syamantaka.
Translation: 
Śukadeva Gosvāmī said: Sūrya, the sun-god, felt great affection for his devotee Satrājit. Acting as his greatest friend, the demigod gave him the jewel called Syamantaka as a token of his satisfaction.