Astral Signet of the Infinite Equation

The Astral Signet is a magnificent ring of blackened platinum, formed from hundreds of interlocking bands so fine they resemble woven strands of moonlight. A deep violet crystal rests above the knuckle, containing a slow-turning galaxy of silver motes. When its wearer invokes a spell, the filigree rearranges itself into arcane formulae, and the gemstone briefly opens like a many-petaled eye. The ring can serve as a spellcasting focus for its attuned wearer.