The stone is coarse grained and dark colored. It contains large crystals. The rim is inverted. It is broken and mended. Fragments are missing. There is no ring at the top.
From Giza, Menkaura (Mycerinus) Valley Temple. excavated by the Harvard University–Boston Museum of Fine Arts Expedition; assigned to the MFA in the division of finds by the government of Egypt.
Harvard University—Boston Museum of Fine Arts Expedition