From an unused root meaning to glisten; shining; a gem, probably the garnet -- emerald.
H5306. nophek
נֹ֫פֶךְ noun [masculine] a precious stone which Tyre gained by trade Ezekiel 27:16 (where ׳נ doubted by Berthol, queried by Toy: Hpt), compare 28:13 (symbolic of wealth and honour of king of Tyre); in high priest's breastplate Exodus 28:18; 39:11. Perhaps = ruby or carbuncle ᵐ5 Joseph. ἄνθραξ, ᵑ9 carbunculus, compare DiEx KauEx SgfrEzek Co Berthol; ᵑ7 AV emerald.