Our favorite feed of the monthIf you want to get caught in an Insta black hole, challenge yourself (and your pals) to an informal game of Guess the Gemstone at @structure_minerals. When you’re done drooling, you can hit the brand’s Etsy store to buy some of the beauties.   Fluorite from Illinois Mixed crystals Brazilian rutilated quartz A slice of tourmaline More tourmaline! Vanadinite from Morocco