Alignment of the polymer molecules within the lamellae results in birefringence producing a variety of colored patterns when spherulites are viewed between crossed polarizers in an optical microscope. In particular, the so-called "Maltese cross" is often present which consists of four dark perpendicular cones diverging from the origin (see right picture), sometimes with a bright center (front picture). Its formation can be explained as follows. Linear polymer chains can be regarded as a linear polarizers. If their direction coincides with that of one of the crossed polarizers then little light is transmitted; the transmission is increased when the chains make a non-zero angle with both polarizers, and the induced transmittance is dependent on the wavelength, partly because of the absorption properties of the polymer.