Apatites in heterotopic calcifications.

Calcified material obtained from three patients suffering from calcifications of the shoulder tendon sheath and from a subcutaneous with calcinosis was studied. A panel of different techniques was applied to this study: scanning electron microscopy, X-ray diffraction, infrared spectrometry, scanning and transmission wavelength dispersive X-ray spectrometry, high resolution transmission electron microscopy and electron microdiffraction. These calcifications, made of carbonate containing apatite, are heterogeneous and composed of at least two separate phases the crystallinity of which appear different.