This jar contains a rare class of materials known as aerogels. Often called “frozen smoke,” their porous structure makes them the world's least dense solids. Their unique properties helped NASA capture space dust in the STARDUST mission. This silica-based aerogel is hydrophobic (repels water) and has fascinating optical qualities. It boasts an incredibly low density, consisting of up to 99.8% air. You'll receive about 5 grams, with several chunks ranging in size, including multiple pieces over 1 inch large. Important: Silica aerogel is a scientific material, not a toy. Do not inhale the powder, do minimize skin contact, and always wash hands after handling. Be gentle, as it easily breaks into fine particles. →MAGIC MATERIALS COMPANY brings you inspiration through materials! From aerogels to nitinol, smart pigments, and more, we search the material world to find high-quality, functional, and hard-to-find products.