Anyone know stories about stone sealing tomb of Christ, on display in Sepulchre church ca. 570-630 A. D?

Reported by pilgrim 570 as adorned with gems and precious metals, may have disappeared 614 when Persians sacked the city and took gems (some returned 630) but no mention of slab. Might have been kept there till 638 Muslim conquest. Might have been octagonal therefore sacred to the Templars.