This quarry with a particularly hard type of limestone was discovered in a neighborhood about a mile west of the Old City of Jerusalem. The destination of the large columns may have been the Nea Church, an enormous basilica located on the southern end of today’s Jewish Quarter. From Haaretz:

Recent construction in the Jerusalem neighborhood Rehavia, may have revealed the site of this miraculous quarry. Under the foundations of an old building demolished to make room for new construction a large stone chiseled in the shape of a column.
Upon discovery of the column, the Israel Antiquities Authority halted the construction project and began studying the find, which is 20 ft (6 m) tall and 30 in (80 cm) wide. These proportions correspond to building practices of the period.
The site had no other finds that could be used to time the column but Evgeny Kagan of the Antiquities Authority, believes that it is from the Byzantine period based of the stone type and the methods used by the stonemasons. The stone bares the Arabic name “Mizi Achmar,” meaning red stone, which could correspond to the “flames of fire” described by Procopius.
This kind of stone is considered very difficult to work with. According to Prof. Yoram Zafrir it was hardly used until the introduction of explosives in the 19th Century, except during the Byzantine era. The builders of the Jerusalem Temple for example used a softer stone.

The full story gives a Byzantine account of the provision of giant red stones. A high-resolution image is viewable here.

HT: Joseph Lauer

A seal from the days of the First Temple has been discovered below the southwestern corner of the Temple Mount. From the press release by the Israel Antiquities Authority:

The remains of a building dating to the end of the First Temple period were discovered below the base of the ancient drainage channel that is currently being exposed in IAA excavations beneath Robinson’s Arch in the Jerusalem Archaeological Garden, adjacent to the Western Wall of the Temple Mount. This building is the closest structure to the First Temple found to date in archaeological excavations.
In the excavations, underwritten by the Ir David Foundation, a personal Hebrew seal from the end of the First Temple period was discovered on the floor of the ancient building. The seal is made of a semi-precious stone and is engraved with the name of its owner: “Lematanyahu Ben Ho…” (“למתניהו בן הו…” meaning: “Belonging to Matanyahu Ben Ho…”). The rest of the inscription is erased.

Two people with the name Mattaniah are mentioned in 1 Chronicles 25:4, 16 and 2 Chronicles 29:13.

The full press release is here. Leen Ritmeyer comments on the location of the find. Joseph Lauer passes on word that some information in the press release is incorrect. According to Zachi Dvira (Zweig), “This was not sifted at our site. And the visitors sift only the debris from the Temple Mount.

Only our staff workers do the sifting for other excavations.”