The Fractured Astrolabe

The Fractured Astrolabe: a pocket-sized, spherical device made of dark, unreflective metal. What it looks like: A series of interlocking, concentric rings that float slightly apart without touching. It looks like a clockwork model of the cosmos, but the runes carved into it are jagged, ancient, and do not match any known mortal language.
The Blueprint: A palm-sized sphere made of Aethel-brass—a matte-black alloy that absorbs all local candlelight. It features seven concentric, razor-thin rings that float suspended in mid-air around a central core. There are no pins, gears, or axles holding them together. They are bound purely by localized gravitational fields.
The Arcane Machinery: The surface of each ring is micro-etched with shifting mathematical algorithms. When a spell is cast nearby, the rings spin rapidly, acting as a literal arcane tuning fork. They don't track stars; they track the geometric frequency of the world's magical ley lines.
The Sabotage: Upon close inspection (using an Artificer's tools or an Arcana check), the outermost ring has been violently disrupted. A series of deep, angular gashes have been carved into the track. It looks as though someone struck it with a weapon forged from null-magic iron or void-steel.

Orinn's Perspective: He found it buried in a ruin a year ago. He thinks it is just a beautifully complex, broken mechanical puzzle. He has been trying to align the rings for months, completely unaware that his subconscious mind is guiding his fingers to solve it.
When held, it doesn't feel like normal metal. It feels like dormant, condensed magical pressure. It is currently in the possession of Orin, a half elven artificer who owns the Unwinding Cog tinker's shop.

The properties of this device are unknown, but it occasionally radiates and pulses with a powerful arcane resonance...