The Second Temple's mysterious smooth stone

Israel Hayom has a nice survey on the state of archaeology along the Western Wall, and it adds this new information:

The recent discovery is fascinating at the very least: a single stone that is different in appearance from the others and raises quite a few questions. It is completely smooth, lacking the cut margins at the edges that we know well from the other stones of the Western Wall.

Where did that stone come from? Why is it there, and why is it different from the stones around it? All the foundation stones of the Western Wall are Herodian stone, also known as ashlar stone, with cut margins and a raised center, called a boss. Even though Herod's stonemasons finished these stones rather coarsely, these stones still bear a close resemblance to the familiar stones of the Western Wall, the ones that are above ground. Of all the stone blocks used to build the Western Wall, only this one is completely smooth, lacking recessed margins and a raised boss.

Eli Shukron explains it with an interesting theory. "This stone came from the Temple Mount, from the surplus stones that were used in the construction of the Temple itself. Those stones were high-quality, chiseled and smooth, like this unusual one, which was discovered among the Western Wall's foundations. This stone was intended for the Second Temple, and stones like it were used to build the Temple -- but it was left unused. The builders of the Western Wall brought it down here because it was no longer needed up above -- and this is how the other stones of the Temple looked," he says, adding, "Anyone who passes a hand gently over this stone feels a slightly wavy texture, just like the Talmud describes."

Shukron presented his theory at an informal meeting of leading archaeologists in Jerusalem that takes place every month or two. Most of the archaeologists did not rule out the possibility that Shukron might be correct, but there is no solid proof.

Dr. Eilat Mazar recently completed the project of documenting the walls of the Temple Mount, which took three years (and was sponsored by the Shalem Center). As part of the project, every single of the walls of the Temple Mount was photographed, researched and numbered. Dr. Mazar confirms Eli Shukron's statements. "Yes -- there is not even one other smooth stone like it among all the stones of the Temple Mount walls. All of them have chiseled margins," she says. Still, Mazar says, "It is hard to construct a theory on the basis of a single stone. If another stone or two like it should be found in the future -- and that could happen -- that will be a somewhat stronger basis for Shukron's theory that the stone came from a surplus that had been intended for the Temple of the type that had been used to build it." Meanwhile, Mazar says, "This is a worthy and interesting idea, but we need to be cautious."