These rubies have been expertly carved into holy symbols of Varkys by blasphemous Tritons. Due to their connection to the god of blood and magic, they are sought after by spellcasters of all kinds. The ruby symbols seem to have etchings of tentacles on their surface.
(requires attunement by a spellcaster)
This carved ruby amulet bears the symbol of Varkys, the Blood God of Life & Magic. To attune to this amulet, you must dip the ruby in the blood of a slain humanoid and focus on it for an hour. If you attempt to attune to the amulet or cast the identify spell on it without performing this ritual, you must succeed on a DC 17 Wisdom saving throw. On a failed save, you take 12d6 psychic damage, taking half of the damage rolled on a success.
While you are attuned to the holy symbol, you gain a +2 bonus to spell attack rolls and the saving throw DCs of your spells. In addition, You have Advantage on saving throws against spells while you wear this symbol.