Bog Oak: Quercus robur: This is oak that fell into a low oxygen, high mineral content bog. This Bog oak is from Ukraine, and has been carbon dated to ~4600 years ago.
For some context, when this tree fell into the bog: Stone hedge was starting construction, the Shang dynasty in China was acceding, the first Bronze artifacts in Greece are noted, and the Egyptian middle kingdom was at its zenith.
Blocks are darker than they appear in photos. To show any grain detail, the photos are slightly overexposed. Expect blocks to be nearly midnight black.