Wondrous item, Rare (requires attunement by a spellcaster).
These are larger, beautiful gemstones cut into perfect icosohedrons. They are large enough to sit comfortably in one's hand.
While you are holding this gem, you can use it as a spellcasting focus for your spells.
Elementally Attuned. The gem has 3 charges and regains all expended charges daily at dawn. When you cast a spell using this gem that deals damage of the associated type, you can expend up to 3 charges to reroll as many damage dice. The types of Deep Gemstones are:
- Ruby: Fire
- Sapphire: Cold
- Topaz: Lightning
- Amethyst: Psychic
- Emerald: Acid
Shock Absorber: Each gemstone has 25 HP. When the user is attuned to the gemstone any damage the user takes of the given type can be transferred to the gemstone. This damage cannot be reduced by resistances or immunities, nor can it be split up by choice - the full amount goes to the gem or the user. If the gem absorbs damage that drops it to 0 hit points, it is
destroyed, and the user takes any leftover damage. The gemstone regains all its hit points at dawn if it has at least 1 hit point
remaining. (Heart of Sorrow Reference)