Archaeologists discovered a ceramic jar containing over 100 gold and silver artifacts at the site of Diriyah.

Archaeologists have unearthed a 1,200-year-old hoard of gold, silver and gemstones that was buried along a medieval pilgrimage route in Saudi Arabia.

Archaeologists in Saudi Arabia have unearthed a clay pot full of gold, silver and gemstone-encrusted jewelry that may have been buried by an Islamic pilgrim en route to Mecca more than a millennium ago.

The team nicknamed the hoard the "Diriyah Treasure" after the archaeological site where it was discovered. Located on the outskirts of Riyadh, Diriyah was a key station on the Hajj route for Islamic pilgrims between Basra, Iraq, and Mecca, Saudi Arabia. According to archaeologists with the Saudi Heritage Commission who have been excavating Diriyah for six years, radiocarbon analysis of organic remains puts the main settlement in the period of 743 to 753.

During the recent excavation season, archaeologists discovered gypsum water basins and the walls of several residential buildings. Inside the structures, they found fragments of pottery and glass — but the buried ceramic jar containing over 100 pieces of jewelry was a surprise.

"One of the most important discoveries of this sixth season was the uncovering of the 'Diriyah Treasure,' which consists of a collection of gold pieces, gemstones and oxidized copper fragments," a laboratory expert with the Saudi Heritage Commission said in a translated video.

Although Diriyah is better known for being the first Saudi state and the original location of the House of Saud (the ruling family of Saudi Arabia) beginning in the 18th century, its history goes back much further.

An aerial photograph of the archaeological excavations at Diriyah.

The treasure hoard was likely buried during the early years of the Abbasid caliphate, which came to power in 750 and was destroyed by the Mongols in 1258. Named after one of Muhammad's uncles, the Abbasid caliphs helped usher in the Islamic Golden Age in which cultural and scientific activity flourished. Geographically, the Abbasid Empire stretched from North Africa to Iran but was concentrated primarily in the Arabian Peninsula and present-day Iraq, with its capital at Baghdad.

According to Islamic tradition, every adult who can afford it and is physically able to make it is supposed to make a pilgrimage — called the Hajj — to the holiest Islamic city, Mecca, at least once. During the Abbasid period, Diriyah was an important stop on the pilgrimage route between Basra, a port city in southern Iraq near the Arabian Gulf, and Mecca on the west coast of Saudi Arabia.

Experts do not yet know why the jewelry decorated with floral patterns and geometric motifs was buried at Diriyah or whether it belonged to a pilgrim. But it is clear that skilled metalworkers crafted the pieces, Gulf News reported, by shaping sheets of gold, embossing them, and inlaying semiprecious gems.

Additional archaeological excavation at Diriyah is planned for the future.