Build Your Own Silicate Minerals

The University of Kentucky's College of Arts and Sciences has a nice interactive activity about silicate minerals. The activity has an overview section in which students read about the structure of silicate minerals before moving to attempt to create silicate mineral models. There are three models for students to try to construct.

Applications for Education 
This isn't a particularly fancy or complex activity, but it could be a good addition to a science teacher's collection of online activities for students.