This bottle contains a rare class of materials known as aerogels. Often called "frozen smoke", their porous structure makes them the least dense solids in the world. Its unique properties helped NASA capture space dust on the STARDUST mission. This silica based aerogel is hydrophobic (water repels) and has fascinating optical qualities. It boasts an incredibly low density, consisting of up to 99.8% air. You will receive about 2 oz, with multiple pieces ranging in size, over one between 0.5 and 1.5 inches. Important: Silica aerogel is a scientific material, not a toy. Do not inhale dust, minimize skin contact, and always wash your hands after handling. Be kind because it easily breaks into fine particles. →MAGIC MATERIALS COMPANY brings inspiration to you through materials! From aerogels to nitinol, smart pigments and more, we've researched the world of materials to find high quality, functional, and hard to find products.