Far Arden delivers these beautiful rocks that you can even buy at Etsy.
“If a unicorn and a rock had a baby, it would be this geode. Geodes start their lives as bubbles in volcanic rock or as animal burrows, tree roots or mud balls in sedimentary rock. Over millions of years, the outer shell hardens, and water forms on the inner walls. If the liquid contains dissolved minerals, it forms crystals within the cavity.”
via: boredpanda