The department houses a laboratory for study of minerals and crystalline substances using X-ray diffraction techniques. Because the wavelength of X-rays are similar to the spacing of atoms in crystals, X-rays are scattered by crystals in much the same way that a diffraction grating scatters light. Discrete angles and intensities of scattering correlate with the geometric pattern of atoms within a crystal. Examination of the pattern and intensities of scattering from a sample are used to interpret its crystal structure and to identify the mineral or crystalline compound constituting the sample.