Graphics3D[{Polygon[{{0.57735, 0, -0.5}, {-0.28868, 0.5, -0.5}, {-0.28868, -0.5, -0.5}}], Polygon[{{0.57735, 0, 0.5}, {-0.28868, 0.5, 0.5}, {-0.28868, -0.5, 0.5}}], Polygon[{{0.57735, 0, -0.5}, {-0.28868, 0.5, -0.5}, {-0.28868, 0.5, 0.5}, {0.57735, 0, 0.5}}], Polygon[{{-0.28868, 0.5, -0.5}, {-0.28868, -0.5, -0.5}, {-0.28868, -0.5, 0.5}, {-0.28868, 0.5, 0.5}}], Polygon[{{-0.28868, -0.5, -0.5}, {0.57735, 0, -0.5}, {0.57735, 0, 0.5}, {-0.28868, -0.5, 0.5}}]}, {LightSources -> {{{1., 0., 1.}, RGBColor[1., 0, 0]}, {{1., 1., 1.}, RGBColor[0, 1., 0]}, {{0., 1., 1.}, RGBColor[0, 0, 1.]}, {{-1., -1., -1.}, RGBColor[0.5, 0.5, 0.5]}}, Boxed -> False, DisplayFunction -> Identity}]