The "Choshen" (breastplate) was worn by the High Priest 'Aharon HaKohen' for the first time, and then by every High Priest in the First and Second Temples.
Each of the 12 stones denoted a different tribe of the 12 Tribes, and was a different color.
Delicate and lively gold filled
"Choshen" 12 Tribes Breastplate design
What is Gold Filled?