a precious stone, emerald, accusative to 𝔊, 𝔙, (both P).
Strong's H1304בָּרֶקֶת: a gem (as flashing), perhaps the emerald KJV:carbuncle.
Meanings: Brown-Driver-Briggs (1906) and Strong's Hebrew Dictionary (1890), public domain, via the Open Scriptures Hebrew Bible Project (CC BY 4.0). TWOT numbers for reference only.
Root family 287: בָּרַקbāraq — flash; to lighten, lightning, gleam, flashing sword; cast forth, bright, glitter