Brushite

Similarly, phosphoric acid contamination resulted in formation of brushite, merlinoite and dawsonite minerals.

The main constituent of calcium stones is brushite (calcium hydrogen phosphate) or hydroxyapatite [31, 32].

In specimens #12 and #75, both containing a significant quantity of carboapatite (60 and 10%, resp.), a tiny quantity below the cutoff limit (<5%) of brushite and/or octacalcium phosphate was also identified by FT-IR spectroscopy.

Calcium oxalate makes up about 60% of all stones; mixed calcium oxalate and hydroxyapatite 20% and brushite stones 2%.

However, EWSL SFRs are significantly decreased under the following circumstances: shock-wave-resistant stones (formed of calcium oxalate monohydrate, brushite, or cystine); the presence of a steep infundibular-pelvic angle; the presence of a long lower pole calyx (>10 mm); and the presence of a narrow infundibulum (<5 mm) (2).

SEM images and XRD analysis of the Ca-P deposit indicated the initial formation of brushite with its monoclinic crystal structure and characteristic peak at 11.76 2[theta], and electrochemical conversion of brushite to hydroxyapatite on silk after electrochemical cathodization as confirmed by XRD and SEM analysis.

In a typical electrochemical deposition, a precursor (brushite) is first formed that is converted into hydroxyapatite (HA) through an ageing process.

Riley, "Transformation of modified brushite to hydroxyapatite in aqueous solution: effects of potassium substitution," Biomaterials, vol.