A precious, brilliant, transparent gemstone that is a variety of beryl. Emerald is composed of aluminum and beryllium silicate and a small amount of chromium that imparts the green color to the stone. It is slightly harder than quartz and is usually found in nodular form or in distinct six-sided crystals.

Emeralds were known to the early Egyptians, who obtained them from Upper Egypt. They were probably among the valuable articles received from the Egyptians just prior to Israel’s departure from Egypt. (Ex 12:35, 36) Later, an emerald (Heb., ba·reʹqeth) was placed as the third stone in the first row of stones on the high priest’s “breastpiece of judgment.” (Ex 28:2, 15, 17, 21; 39:10) The king of Tyre is depicted as wearing a covering of “every precious stone,” including the emerald, in the prophetic dirge delivered by Ezekiel.​—Eze 28:12, 13.

The apostle John, in his vision of Jehovah’s heavenly throne, used the emerald to describe the rainbow that was “round about the throne.” (Re 4:1-3) When John saw “the holy city, New Jerusalem,” he observed that “the foundations of the city’s wall were adorned with every sort of precious stone,” the fourth being emerald (Gr., smaʹra·gdos).​—Re 21:2, 10, 19.