T. Kodaka et al., SCANNING ELECTRON-MICROSCOPY AND ENERGY-DISPERSIVE X-RAY-MICROANALYSIS STUDIES OF SEVERAL HUMAN CALCULI CONTAINING CALCIUM-PHOSPHATE CRYSTALS, Scanning microscopy, 8(2), 1994, pp. 241-257
Human calcium phosphate calculi: two sialoliths, a urolith, a rhinolit
h, and a tonsillolith were investigated by scanning electron microscop
y (SEM) and energy-dispersive X-ray analysis (EDX). The sialoliths and
urolith had appositional shells with thick cortices, respectively, ar
ound several nuclei composed of calcospherulites and a rubber-film fra
gment. The rhinolith had a thin cortex with appositional laminations a
round a glomerulus-like mass of calcified cotton-like strings. The ton
sillolith had a rough cortex with appositional laminations. Its porous
interior was composed of numerous calcified conglomerates with microo
rganisms and calcified masses with fine appositional laminations aroun
d the conglomerates. The major crystals were identified as biological
apatites (AP) with a sand-grain rather than a needle-like shape, and p
late-shaped octacalcium phosphate (OCP). The AP deposits of the rhinol
ith probably were associated with magnesium (Mg) phosphates or contain
ed Mg. No OCP was found in the rhinolith. The AP deposits were mainly
formed by extracellular calcification. Hexahedral crystals, identified
as Mg-containing whitlockite (WH), were precipitated in the internal
spaces of the AP and OCP deposits. The rhinolith nucleus consisted of
WH crystal deposits only.