This root form (lemma) is used in 2 different forms in the NT: σάρδιον (NNS), σαρδίῳ (DNS).
It is glossed in 1 way: ‘sardius’.
OET REV 4:3 Greek word=σαρδίῳ (sardiōi) Morphology=DNS English gloss=‘sardius’ SR GNT REV 4:3 word 13
OET REV 21:20 Greek word=σάρδιον (sardion) Morphology=NNS English gloss=‘sardius’ SR GNT REV 21:20 word 8