Here's a lovely specimen of the very rare potassium-sodium-lithium silicate Polylithionite with aegerine from the Poudrette Quarry, Mont St. Hilaire, Quebec, Canada. in this specimen, sharp, rounded sheet-like crystals in a pearly iridescent color form robust rosettes, alongside sprays of black aegerine crystals on a light-colored matrix. We picked this up at the Tucson Gem, Rock & Mineral Show in Arizona.