The Hebrew word odem (אֹדֶם) refers to a red gemstone — traditionally identified as ruby, carnelian, or sardius. It was the first stone in the first row of the High Priest's breastplate and is mentioned among the jewels of Eden.
The odem as the first stone on the High Priest's breastplate carried the name of Reuben, the firstborn of Israel. The breastplate's stones represented the twelve tribes carried over the priest's heart as he approached God — a picture of Christ, our great High Priest, who carries His people before the Father. The appearance of odem in the Garden of Eden (Ezekiel 28:13) and in the New Jerusalem's foundations (Revelation 21:20) connects this stone to both original glory and eschatological restoration.