A sample of the hexadecahydrate of <a href="https://en.wikipedia.org/wiki/Aluminium_sulfate" class="extiw" title="w:Aluminium sulfate">aluminium sulfate</a>.
Picture taken by <a href="https://en.wikipedia.org/wiki/User:Walkerma" class="extiw" title="w:User:Walkerma">Martin Walker</a> in June 2005.
2005-06