A window assembly includes a first pane of glass. The first pane of glass is chemically strengthened and exhibits a surface compressive stress of 400 MPa or more. A second pane of glass has a first major surface and a second major surface. The second major surface of the second pane of glass and a first major surface of the first pane of glass face each other. The second pane of glass includes 68-74 weight % SiO