As a scientist involved in crystallography i have come across a kids toy called MAGNEXT. With these units one can construct pretty cheaply octahedral and tetrahedral units, with these one can then help construct larger standard mineral structures/arrangements. For teaching this very dull subject this could be ideal?
peter.swash from alcoa.com.au <mhtml:{71EDF8F3-562E-48EB-BA47-A18B8CDC741A}mid://00000000/!x-usc:mailto:peter.swash@alcoa.com.au>
