The fifteenth ink of the engraved manuscript. Copper carbonate quarried from the Ural Mountains, banded green like a slow agate, ground in stone mortars for the green of medieval foliage.
This stone has fifteen bands. Each rings a different pitch — the deepest band at the core sounds lowest, the outermost ring sounds highest. The banding is real malachite; the pitch progression is one semitone per band.
Click any band to ring it. Click the center to play all fifteen in sequence, lowest to highest.