Marrow sucking stone

Marrow sucking stone is a rank seven immortal material. It is black and looks like an ordinary rock by the beach, but any life form with bone marrow that gets close is sucked inside. Gu Immortals treat it as an immortal material; one trader offers it for thousand year floating wood at an Eastern Sea convention. ^{ch. 1297}

Mermen coined the name demon stone for it. Most mermen live in Eastern Sea, can breathe underwater, and have suffered from marrow sucking stones, so they fear them under that name. In Eastern Sea history, some merman tribes treated these demon stones as deities to worship. ^{ch. 1297}

Marrow sucking stone is named among a large stock of earth path immortal materials packed into an immortal aperture when preparing for tribulation. ^{ch. 2133}