Declension table of ?gururatna

Neuter	Singular	Dual	Plural
Nominative	gururatnam	gururatne	gururatnāni
Vocative	gururatna	gururatne	gururatnāni
Accusative	gururatnam	gururatne	gururatnāni
Instrumental	gururatnena	gururatnābhyām	gururatnaiḥ
Dative	gururatnāya	gururatnābhyām	gururatnebhyaḥ
Ablative	gururatnāt	gururatnābhyām	gururatnebhyaḥ
Genitive	gururatnasya	gururatnayoḥ	gururatnānām
Locative	gururatne	gururatnayoḥ	gururatneṣu

Compound gururatna -

Adverb -gururatnam -gururatnāt