• Formula: Na₈(Al₆Si₆O₂₄)Cl₂
• Mohs: 5.5 to 6

This gorgeous blue-hued gemstone is sodalite. She’s so pretty that even royals have been enamored with it, and who can blame them? But these pretty blue rocks catch more than just eyes. Their molecular structure is the basis for some of the most precise filtering systems out there, which are vital in all kinds of applications. 

The filters we’re talking about are zeolites, and they’re microscopic, porous silicates that have such tiny pockets that they can catch individual molecules. They’re used in water softeners and laundry detergents because they can catch calcium ions, as catalysts in the process of making gasoline from ethanol, and even in kitty litter. Zeolites can even help process radioactive nuclear waste and safely remove it from contaminated environments. Nowadays, scientists can engineer the perfect zeolites for whatever task they need, but naturally-occurring sodalite was the blueprint - no pun intended!