Schertelite mineral
Schertelite is the hydrated magnesium hydrogen-phosphate mineral species (NH4)2Mg(PO3OH)2(H2O)4. The September 2026 IMA list gives grandfathered status and original-description year 1902, not a new-mineral approval identifier. It is distinct from elemental phosphorus or magnesium, struvite, other phosphate mineral species and mixed culture precipitates. Constituent criticality is not inherited. The culture evidence below is a bounded assignment of a minor recovered phase, not a purified product or established direct metabolic pathway.
Microbial & Biochemical Mechanisms (2)
Schertelite-assigned minor phase in static bacterial cultures
biomineralization
Microbial
Powder diffraction of dried products from Myxococcus coralloides D cultures was interpreted as schertelite occurring with dominant struvite under selected static liquid-medium conditions. The accepted observation is the recovered source-assigned phase associated with a culture; direct microbial causality and product yield remain unresolved.
Experimental Context & Analytical Limits:
The thesis used a live laboratory culture historically named Myxococcus coralloides D, described as a dispersed-growth derivative obtained by successive liquid passage; the Methods also calls it Corallococcus coralloides. No deposited stock or sequence accession is supplied for D, so no exact modern strain identifier is inferred. Static cultures were aerobic at 28 degrees C. CT medium used 1% Bacto-Casitone and a 10 mM potassium-phosphate buffer. Table 8 associates the target phase with CT-2 (initial pH 6.8; nominal Mg 4.06 mM from MgSO4.7H2O), CT-13 (10 mM phosphate/10 mM Mg), and CT-15 (10 mM phosphate/20 mM Mg); CT-13/15 derive from the pH 6.5 base recipe. Methods permits 3 mL tube cultures inoculated with 0.1 mL of a 50-hour culture or 100 mL in 250 mL flasks inoculated with 3.3 mL; the target-phase table does not map each diffractogram to vessel size. Static products were collected after 20-22 days by decanting, repeated distilled-water washing and room-temperature drying. The dried mixed products were ground and examined by powder XRD using reference-pattern comparison. No boiling agar extraction applies to these liquid-culture target observations.
The thesis used a live laboratory culture historically named Myxococcus coralloides D, described as a dispersed-growth derivative obtained by successive liquid passage; the Methods also calls it Corallococcus coralloides. No deposited stock or sequence accession is supplied for D, so no exact modern strain identifier is inferred. Static cultures were aerobic at 28 degrees C. CT medium used 1% Bacto-Casitone and a 10 mM potassium-phosphate buffer. Table 8 associates the target phase with CT-2 (initial pH 6.8; nominal Mg 4.06 mM from MgSO4.7H2O), CT-13 (10 mM phosphate/10 mM Mg), and CT-15 (10 mM phosphate/20 mM Mg); CT-13/15 derive from the pH 6.5 base recipe. Methods permits 3 mL tube cultures inoculated with 0.1 mL of a 50-hour culture or 100 mL in 250 mL flasks inoculated with 3.3 mL; the target-phase table does not map each diffractogram to vessel size. Static products were collected after 20-22 days by decanting, repeated distilled-water washing and room-temperature drying. The dried mixed products were ground and examined by powder XRD using reference-pattern comparison. No boiling agar extraction applies to these liquid-culture target observations.
Curated Evidence Points:
Partial
Source:
entrena_1994
Printed page 107 Table 8 and Figure 19 on page 108 (CT-2 and CT-15), Figure 21 on page 110 (CT-2 and CT-13), and Figure 22 on page 111 (CT-2) assign schertelite to recovered mixed crystalline products. The phase was reported only in static cultures. These source assignments support culture association, with the analytical and control limitations below.
Partial
Source:
entrena_1994
Printed pages 107-111 and 137-139 do not report phase-specific sterile or killed-cell control results, quantitative phase refinements, replicate counts or a phase-specific P/Mg mass balance. Peaks and shoulders were assigned within dominant struvite patterns, and the authors explain that shared elemental composition makes SEM-EDX unable to identify these minor phases independently. Their approximate order-of-5%-or-less abundance and 43% detection statement are not accepted as quantitative recovery, phase purity or replicate-resolved frequency. The comparison to shaken cultures is confounded by harvesting those after 10-12 days instead of 20-22 days. The thesis proposes metabolism, autolysis and local chemistry; it does not establish a target-specific enzyme, gene or obligate biological crystallization pathway. Its cellophane experiments concern struvite and are not transferred as direct controls for the minor target phase. Laboratory culture products do not establish natural formation or industrial recovery.
Partial
Source:
entrena_1994
Discussion page 138 attributes ammonium supply to metabolism of the nitrogenous medium, but no target-specific ammonium balance establishes its source. The recipe has no deliberate inorganic ammonium addition; the reagent-impurity appendix on page 75 nevertheless lists trace ammonium in magnesium sulfate. No claim that every ammonium ion was bacterially generated is made. The exact role of autolysis and heterogeneous nucleation in schertelite formation remains proposed.
Context_only
Source:
frazier_1963
Pages 639-641 report rapid incongruent dissolution of synthetic schertelite in water to form struvite. This makes repeated water washing of the culture precipitates a relevant preservation limitation; the direction or magnitude of any handling-induced change in the thesis samples was not measured. Separate abiotic synthesis does not disprove the culture-associated phase observation or establish a microbial enhancement.
Abiotic schertelite crystallization and aqueous alteration
other
A separate chemical study prepared synthetic schertelite without microorganisms and reported its incongruent dissolution to struvite in water. This independently bounds any claim that the phase requires microbial activity.
Experimental Context & Analytical Limits:
Frazier et al. prepared coarse crystals at 25 degrees C by adding 8.6 g magnesium acetate, hydration unspecified, to 32.2 g NH4H2PO4 and 3.1 g ammonium acetate in 100 mL water. Washed, acetone-rinsed and air-dried crystals underwent chemical, optical and X-ray examination. This is concentrated reagent chemistry, distinct from the bacterial medium and not a matched abiotic culture control.
Frazier et al. prepared coarse crystals at 25 degrees C by adding 8.6 g magnesium acetate, hydration unspecified, to 32.2 g NH4H2PO4 and 3.1 g ammonium acetate in 100 mL water. Washed, acetone-rinsed and air-dried crystals underwent chemical, optical and X-ray examination. This is concentrated reagent chemistry, distinct from the bacterial medium and not a matched abiotic culture control.
Curated Evidence Points:
Support
Source:
frazier_1963
Pages 638-639 describe the preparation and give chemical analyses, optical properties and selected-crystal diffraction; Table 1 page 636 gives the powder pattern. Page 639 reports rapid incongruent dissolution in water with struvite formation, reiterated on page 640. Neither an isolated product yield nor a numerical dissolution rate is supplied.
Partial
Source:
frazier_1963
The proposed surface alteration after several months in air was inferred chemically; the colloidal products were not identified by petrography or XRD. The abstract says hydrolysis produces struvite and schertelite, whereas the body separately describes schertelite-to-struvite and hannayite-to-newberyite-plus-struvite. The specific body observations are retained with this conflict; no universally balanced transformation or industrial deployment is asserted.
Sources & References
-
ima_2026_09: IMA-CNMNC. The New IMA List of Minerals, September 2026. Pages 1-2 definitions; newberyite page 154 and schertelite page 194. Previously acquired official original re-inspected on 14 October 2026.
https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-14) -
entrena_1994: Entrena Guadix, Manuel Alfredo (thesis defended 1994; institutional publication metadata 1995). Producción de estruvita y otras formas cristalinas por Myxococcus coralloides D. Doctoral thesis, Universidad de Granada; institutional handle 10481/14393. Methods printed pages 62-75, Results 107-111 with Table 8 and Figures 19-22, Discussion 137-139; complete 198-page deposited scan acquired and relevant original pages visually inspected.
https://hdl.handle.net/10481/14393 (accessed 2026-10-14) -
frazier_1963: Frazier, A. William; Lehr, James R.; Smith, James P. (1963). The magnesium phosphates hannayite, schertelite and bobierrite. American Mineralogist 48:635-641. Complete seven-page Mineralogical Society of America original inspected, including powder patterns in Table 1 and preparations/alteration on pages 638-641.
https://msaweb.org/AmMin/AM48/AM48_635.pdf (accessed 2026-10-14)
Curation History
| Timestamp | Curator | Action | Summary |
|---|---|---|---|
2026-10-14T09:21:17.323717+00:00 |
codex (GPT-6; codex) | CREATE | Created a distinct phosphate mineral record with inspected primary culture-phase evidence, explicit analytical and causal limits, and independently reported abiotic phase context. |
Record source: data/records/schertelite.yaml