About two million Muslims visit Mecca during the hajj pilgrimage each year to seek forgiveness, grow closer to God and cleanse their souls of sins. And if they're lucky they might even get to touch or kiss the historic and sacred "Black Stone of Mecca."

During a recent episode of The UnXplained, host William Shatner told Discovery channel viewers about the fascinating history of the stone and how it could have otherworldly origins.

According to the Muslim faith, the stone is said to have fallen from heaven. Where it touched down marked the exact location where the the first mosque, the Kaaba, was built by the biblical Abraham and his son, Ishmael.

In modern-day Mecca, Saudi Arabia, the Kaaba is a cube-like, 43-foot-tall black granite structure at the center of the Grand Mosque courtyard. And mounted into the eastern corner of the Kaaba, behind a silver frame, is the Black Stone of Mecca. The exposed face of the stone measures 20 cm (7.9 in) by 16 cm (6.3 in).

The curious stone is actually an amalgamation of eight or more smaller stones that have been cemented together. Gem experts who have viewed the stone believe it could consist of basalt, agate or obsidian rock. It might also be a meteorite, which could explain its heavenly origin story.

The difficulty in putting the speculation to rest is the fact that this stone may never be released for gemological analysis because of its religious significance.

Shatner told his viewers that in the year 605 AD, the stone was set into the Kaaba's wall by the Islamic prophet Muhammad.

After his conquest of Mecca in 630 AD, Muhammad is said to have ridden around the Kaaba seven times on his camel, touching the Black Stone with his stick each time around in a gesture of reverence and humility.

In current days, the Muslim faithful honor Muhammad by walking around the Kaaba seven times. Some of the pilgrims who can maneuver to the inner-most circular path will be fortunate enough to touch the stone or even kiss it.

So, you may be wondering why the stone seems to be fractured, pieced together and then cemented into place.

Ancient-origins.net explained that the Black Stone was damage during the Umayyad siege of Mecca in 683 AD. It was reportedly struck and smashed to pieces by a stone fired from a catapult.

In his book, Travels in Arabia, Swiss adventurer Johann Ludwig Burckhardt got close enough to the Black Stone during a trip to Mecca in 1814 to provide this first-hand report: "It is an irregular oval, about seven inches (18 cm) in diameter, with an undulated surface, composed of about a dozen smaller stones of different sizes and shapes, well joined together with a small quantity of cement, and perfectly well smoothed. It looks as if the whole had been broken into as many pieces by a violent blow, and then united again."

Over time, the stone reportedly has become smoother and darker due to the enormous number of pilgrims who have touched and kissed the stone.

Credit: Screen capture of photo of Black Stone of Kaaba via YouTube / History. Wide view of Kaaba Al-Musharrafah by LaachirDeeper, CC0, via Wikimedia Commons. Photo of Kaaba by Aiman titi, CC BY-SA 3.0, via Wikimedia Commons.

Book My In-store Design Appointment

Have you been thinking about getting a custom piece made, but not sure what the next steps are? Book a no-strings design appointment, and our jewelers will walk you through the design process and educate you about the different stones and metals you're considering.

Choose from the calendar below the best date and time for your appointment. Once you’ve booked your appointment, you’ll receive an email confirming your appointment, and an event invitation to put in your calendar. See you soon!