Key to the house of God?

That'll be $18.1 million, please. BBC reports:

The key to the Kaaba - the ancient cube-shaped shrine in Mecca - went to an anonymous bidder at Sotheby's.

The auction house said the price set a record for the sale of an Islamic work of art.

Made of iron and measuring 37cm in length, the key is engraved with the words "This was made for the Holy House of God".

The key was the centrepiece of Sotheby's Islamic art sale, which realised more than $40m (£21.5m) in total.

According to Bloomberg, the key went for 20 times its estimated value, quite possibly because it was the only one left in private hands. (The 58 other ceremonial keys are held by museums, and the original keys remain with the Bani Shaybat tribe in Saudi Arabia, charged with the shrine's upkeep.) Its rarity certainly buoyed the total take of more than $40 million, more than twice Sotheby's previous record.

Fellow high-end auction block Christie's also broke its record on Tuesday, raising more than $23 million in sales of Islamic art. Which raises the question: Is this an anomaly in an unpredictable market, or a growing trend?

It's certainly hard to say what's fueling the demand. Since the buyers were anonymous, their reasons remain their own. But keep in mind, the lucky bidder won what was once a privilege reserved for the caliph: symbolic access to the holiest shrine of Islam: literally a "black box." The symbolism of the purchase in these Islamo-fascinated times is pretty hard to miss.