All items that can be salvaged for a Lump of Charcoal can be found here.
“Stone Remnants are salvage items dropped by Stone Guardians. Stone Crusher, Stone Rain, Stone...Stone Remnants
“Location: Ice Floe just outside of Marhan's Grotto Collecting: 7 Frigid Hearts Location: Talus...Frigid Heart
“Location: Zin Ku Corridor Collecting: 5 Soul Stones Location: Imperial Sanctum Collecting: 5...Soul Stone
“Location: Talmark Wilderness northeast of the entrance from Majesty's Rest Collecting: 5...Glowing Heart
“There are no known collectors at this time. Burning Titan, Dark Titan, Earth Born Titan, Fist of...Molten Claw