Mode of occurrence of brushite and whitlockite in a sialolith

A micro-focus X-ray diffractometer was applied to a ground section of sialolith, and localization of brushite and whitlockite was found. The sialolith was composed of a central core of organic material and a layered cortex of mineral components. The major component of the mineral cortex is apatite. Brushite and whitlockite locate independently at the surface layer of the cortex.