Transformation of amorphous calcium phosphate to crystalline
dahlite in the radula teeth of chitons.
The phosphorites are of pelletal type and commonly contain cellophane,
dahlite, francolite, glaucophane, dolomite, iron oxide and pyrite in various proportions.
In this work we have studied a small felsic cupola of the southern part of the CIZ related to two types of mineralizations: i) an intra-granitic D cassiterite-bearing vein-complex, usually related to greisen-like alteration, ii) an exo-granitic Prich ore of hydrothermal apatite (
dahlite)-quartz veins (Vindel et al, 2014; Locutura et al., 2007).
Apatite phase contains 4-8% carbonate by weight, referred to as
dahlite. Mineral composition will vary with age and is always subject to calcium deficiency where carbonate and phosphate ions are in the crystal lattice.