On pages 46-47 of the 5e DMG, under the section regarding the Astral Plane, it states:
Visitors occasionally stumble across the petrified corpse of a dead god.
Is there any lore about the composition of a dead god and the potential uses for it?
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Sign up to join this communityOn pages 46-47 of the 5e DMG, under the section regarding the Astral Plane, it states:
Visitors occasionally stumble across the petrified corpse of a dead god.
Is there any lore about the composition of a dead god and the potential uses for it?
One example is the morkoth, as described in Volo's Guide to Monsters.
Spawned by a God. Long ago, a deity of greed and strife perished in the battles among the immortals. Its body drifted through the Astral Plane, eventually becoming a petrified husk. This corpse floated up against a pearlescent remnant of celestial matter imbued with life and life-giving magic. The collision shattered both objects and released a storm of chaotic energy. Countless islands of mixed matter spun away into the silvery void. Within some of them, a vein of pearl-like material held a bit of the deity's rejuvenated supernatural vitality, which spontaneously created a habitable environment. On those same islands, bits of the god's petrified flesh came back to life, in the form of tentacled monstrosities brimming with malice and greed. Ever since that time, each morkoth has had an extraplanar island to call home.
Volo's Guide to Monsters, p.177
From this we can gather the following:
Dungeon 100 gives us an adventure to the Lich-Queen's palace in Tu'narath, built on a dead god known only as The One In The Void. Caverns beneath the palace lead to the petrified heart of the faded god, which contains chambers perfused with emotion, ectoplasmic residues, and in one place the "breath" of the dead god, which provides a one-time permanent benefit to characters encountering it.
If you're looking for uses for god-rock or god-dust or what have you... that I can't help with. The unique properties of the Lich-Queens palace come from the obsidian-like material she built it from and the huge number of spells she laid down on it.
According to A Guide to the Astral Plane, p.38, a dead god's corpse can be mined for a variety of things, including:
Dragon #240 provides some suggestions for what might be found in a god's corpse, ranging from the mundane (fresh water, normal blood, normal plants of rare color) to the magical (liquid potions, energy fields which restore memories or dispel magic, minerals which absorb psionic energy, sentient plant creatures, ingredients of ink which can only be seen by elves, etc).
A Guide to the Astral Plane, p.36, defines that what we think of as a "dead god" is not its original body—a deity's body is really just a vehicle or tool. Its true essence, the part that solidifies into a stone island in the Astral, is its thoughts:
"...The corpse of a god is not flesh. Flesh is inconsequential to divinity. The corse of a god is memories, wars, heroes, regrets, sacrifices, prayers – the stuff of significance."
Those who stand on the god's corpse occasionally find themselves experiencing memories or emotions associated with the deity. If strong enough, the dead god's memories can even temporarily create entire real landscapes, cities, or creatures. A god's corpse can also have its own gravity, and the passage of time may continue normally there (a rare phenomenon in the Astral).
A side-effect of the death of a deity is the Hunefer (Epic Level Handbook p.199), a slain demigod's abandoned physical body which raises as an undead and seeks to rejoin with the original deity.
A potential use?
To the extent that Norse mythology has been included in DnD (at least the pantheon is part of the PHB), you could consider the Norse story of creation, particularly what happened when the mighty Ymir [1] died:
Odin and his brothers slew Ymir and set about constructing the world from his corpse. They fashioned the oceans from his blood, the soil from his skin and muscles, vegetation from his hair, clouds from his brains, and the sky from his skull. Four dwarves, corresponding to the four cardinal points, held Ymir’s skull aloft above the earth.
From https://norse-mythology.org/tales/norse-creation-myth/
[1] While never worshipped as a god, he was certainly god-tier.
Every edition of D&D has spells for raising the dead. You might not be able to do anything in particular with bits of god corpse as materials, but you could also raise dead (or, more likely, appropriate other spell that raises ancient dead deities instead of peasant victims of local sawmill accidents) and then you have a live god.
Bringing dead gods back to life often causes a lot of trouble, though.