Declension table of ?purāṇaratna

Neuter	Singular	Dual	Plural
Nominative	purāṇaratnam	purāṇaratne	purāṇaratnāni
Vocative	purāṇaratna	purāṇaratne	purāṇaratnāni
Accusative	purāṇaratnam	purāṇaratne	purāṇaratnāni
Instrumental	purāṇaratnena	purāṇaratnābhyām	purāṇaratnaiḥ
Dative	purāṇaratnāya	purāṇaratnābhyām	purāṇaratnebhyaḥ
Ablative	purāṇaratnāt	purāṇaratnābhyām	purāṇaratnebhyaḥ
Genitive	purāṇaratnasya	purāṇaratnayoḥ	purāṇaratnānām
Locative	purāṇaratne	purāṇaratnayoḥ	purāṇaratneṣu

Compound purāṇaratna -

Adverb -purāṇaratnam -purāṇaratnāt