- Identification of crystalline phases contained in unknown samples

- Quantitative determination of the weight fraction of crystalline phases in multiphase materials

- Characterization of solid-state phase transformations

- Lattice-parameter and lattice-type determinations

- Orientation of single crystals

- Stereographic projections

- Alignment for cutting along crystallographic planes

- Qualitative and quantitative analysis of crystalline phases in coal ash, ceramic powders, corrosion products, and so on

- Determination of phase diagrams

- Determination of pressure- and/or temperature-induced phase transformations

- Quantitative analysis of solid solutions from lattice-parameter measurements

- Determination of anisotropic thermal expansion

- Form: Crystalline solids (metals, ceramics, geological materials, and so on)

- Size: For powder samples 1 mg is usually adequate

- Preparation: Sometimes none; sample may require crushing to fit into the sample holder

- Must be crystalline for phase identification

- Identification requires existence of standard patterns: JCPDS powder diffraction file of inorganic and organic phases, NBS Crystal Data (contains lattice constants for inorganic and organic phases), and Cambridge File of Organic Single Crystal Structural Data

- Qualitative analysis requires less than 1 h for major phases, up to 16 h for trace phase confirmation

- Quantitative analysis, after a procedure is set up, requires several minutes to several hours

- X-ray spectrometry, inductively coupled plasma atomic emission spectroscopy, atomic absorption spectrometry, classical wet chemical analysis: Quantitative and qualitative elemental information

- Auger electron spectroscopy: Elemental and structural data on small portions of the samples

- Single-crystal x-ray diffraction: Crystal structure using small single crystals

- Infrared and Raman spectroscopy: Molecular structure and sometimes crystal structure

- Neutron diffraction: Similar information, but can be applied in some cases in which x-ray powder diffraction fails