Colorless heavy optical glass; ground and polished. (A) Triangle with triangular corners, two sides polished. (B) Six- sided prism with two corners cut into triangles, our sides polished. (C) Four corners cut into triangles, on top a deep curved notch, three sides polished. (D) Prism with four large polished sides and three small unpolished sides, two corners cut into triangles. (E) Spherical object, one side flattened, one side with a circular disc knop the other one with a pedestal- like extension, painted black in such a way that there are four circular windows including flattened side.