- Sold by the Undead Female Merchant for 10 souls each.
- Sold by Patches for 10 souls each.
- Sold by Hawkeye Gough (AotA) for 10 souls each.
- Found in a chest right before the outdoors section of The Duke's Archives.
Drops a brightly glowing stone in front of the player, with a short (but unskippable) animation. If there is a light twinkling sound upon the stone landing, then the player will survive the fall if they jump off the ledge with full Health. If a scream is heard upon impact, then the fall is fatal. There are 8 colors of prism stone. The colors serve no purpose other than aesthetic. The colors are purple, red, yellow, green, white, light blue, blue, and pink.
Prism Stones are a useful utility item in many ways. In addition to their usefulness in gauging falling safety, they can serve as path markers or reminders, and can help prevent new players from getting lost. They are also useful in making sure that the path ahead is safe. This is particularly useful in the darkness of the Tomb of the Giants, and on the invisible walkways of the Crystal Cave.
- Prism Stones can be used to weigh down pressure plates in Sen's Fortress.
- One Prism Stone per playthrough can be traded to Snuggly the Crow for a Demon Titanite.