Caption: These particles resembling microscopic balls of knitting wool are actually inorganic zeolite particles. The microporous crystalline particles are formed via precipitation as the aluminosilicate colloidal hydrogels evolve, starting as an aqueous mineral solution, then becoming a viscoelastic gel and ultimately a soft glassy solid. Credits: Image: courtesy of the researchers Terms of Use: Images for download on the MIT News office website are made available to non-commercial entities, press and the general public under a Creative Commons Attribution Non-Commercial No Derivatives license. You may not alter the images provided, other than to crop them to size. A credit line must be used when reproducing images; if one is not provided