Portable x-ray analysis apparatus for illuminating a sample spot with an x-ray beam, comprising: an x-ray tube tubular in shape having a source spot at one end thereof from which a diverging x-ray beam is produced, the source spot requiring alignment along a transmission axis passing through the sample spot, wherein the apparatus further comprises: a first housing section to which the x-ray tube is attached along a first axis thereof, the first housing section including adjustable tube-mounting features (212, 214) about its perimeter for adjustably mounting the x-ray tube therein such that the source spot coincides with the first axis, the first housing section further including mating surfaces aligned to the first axis; a second housing section having a second axis coinciding with the transmission axis, and mating surfaces aligned to the second axis; and first and second, different x-ray optics (223, 225) attached to the second housing section for receiving the diverging x-ray beam and directing the beam toward the sample spot at different respective energies, the different x-ray optics optic (223, 225) are adjustably mounted to the second housing section by optic carriages (222, 224) for aligning the x-ray optics (223, 225) to the second housing section and to the transmission axis; the first housing section and second housing section being matable along their respective mating surfaces (228, 216) to thereby align the first and second axes with the transmission axis, thereby aligning the source spot, x-ray optics, and sample spot; wherein the first and second housing sections are tubular in shape, and the mating surfaces of the first and second housing sections comprise surface portions in contact with each other upon attachment of the first and second tubular housing sections, wherein the x-ray optics are curved diffracting optics, for receiving the diverging x-ray beam from the x-ray tube and focusing the beam at the sample spot, wherein the x-ray optics are focusing monochromating optics. an x-ray tube tubular in shape having a source spot at one end thereof from which a diverging x-ray beam is produced, the source spot requiring alignment along a transmission axis passing through the sample spot, wherein the apparatus further comprises: a first housing section to which the x-ray tube is attached along a first axis thereof, the first housing section including adjustable tube-mounting features (212, 214) about its perimeter for adjustably mounting the x-ray tube therein such that the source spot coincides with the first axis, the first housing section further including mating surfaces aligned to the first axis; a second housing section having a second axis coinciding with the transmission axis, and mating surfaces aligned to the second axis; and first and second, different x-ray optics (223, 225) attached to the second housing section for receiving the diverging x-ray beam and directing the beam toward the sample spot at different respective energies, the different x-ray optics optic (223, 225) are adjustably mounted to the second housing section by optic carriages (222, 224) for aligning the x-ray optics (223, 225) to the second housing section and to the transmission axis; the first housing section and second housing section being matable along their respective mating surfaces (228, 216) to thereby align the first and second axes with the transmission axis, thereby aligning the source spot, x-ray optics, and sample spot; wherein the first and second housing sections are tubular in shape, and the mating surfaces of the first and second housing sections comprise surface portions in contact with each other upon attachment of the first and second tubular housing sections, wherein the x-ray optics are curved diffracting optics, for receiving the diverging x-ray beam from the x-ray tube and focusing the beam at the sample spot, wherein the x-ray optics are focusing monochromating optics. a first housing section to which the x-ray tube is attached along a first axis thereof, the first housing section including adjustable tube-mounting features (212, 214) about its perimeter for adjustably mounting the x-ray tube therein such that the source spot coincides with the first axis, the first housing section further including mating surfaces aligned to the first axis; a second housing section having a second axis coinciding with the transmission axis, and mating surfaces aligned to the second axis; and first and second, different x-ray optics (223, 225) attached to the second housing section for receiving the diverging x-ray beam and directing the beam toward the sample spot at different respective energies, the different x-ray optics optic (223, 225) are adjustably mounted to the second housing section by optic carriages (222, 224) for aligning the x-ray optics (223, 225) to the second housing section and to the transmission axis; the first housing section and second housing section being matable along their respective mating surfaces (228, 216) to thereby align the first and second axes with the transmission axis, thereby aligning the source spot, x-ray optics, and sample spot; wherein the first and second housing sections are tubular in shape, and the mating surfaces of the first and second housing sections comprise surface portions in contact with each other upon attachment of the first and second tubular housing sections, wherein the x-ray optics are curved diffracting optics, for receiving the diverging x-ray beam from the x-ray tube and focusing the beam at the sample spot, wherein the x-ray optics are focusing monochromating optics.