Barićite mineral
Barićite is a hydrated magnesium phosphate mineral species. The September 2026 IMA list gives the approved formula Mg3(PO4)2(H2O)8 and approval number 1975-027. It remains distinct from bobierrite, elemental magnesium or phosphorus, and mixed recovered precipitates. The historical experimental source uses baricite and a mixed (Mg,Fe) formula; its phase assignment is retained as reported, not a measurement proving the current ideal composition. No criticality designation is inherited from constituents.
Microbial & Biochemical Mechanisms (1)
Barićite-assigned mixed precipitates in hydrogen-fed sulfate-reducing cultures
biomineralization
Microbial
Associated Organisms:
Oleidesulfovibrio alaskensis G20 (NCBITaxon:207559)
Hydrogen-fed G20 cultures in acetate-containing, nutrient-enriched marine pore-water medium formed recovered solids assigned by XRD to barićite, a magnesium-phosphate decahydrate, calcite and elemental sulfur. Sterile counterparts contained mainly amorphous material and calcite. The evidence supports culture-associated phase selection in this laboratory system, without demonstrating enhanced net magnesium removal or a unique molecular nucleation mechanism.
Experimental Context & Analytical Limits:
The living strain is called Desulfovibrio alaskensis G20 in Han et al.; NCBI now resolves it as Oleidesulfovibrio alaskensis G20. Each 120-mL serum bottle contained 100 mL synthetic medium and an iron finishing nail, with a one-hour sterile hydrogen purge and butyl-rubber closure. Two drops of fresh G20 culture were added per inoculated bottle; drop volume and cell density were not specified. Duplicate inoculated and duplicate uninoculated bottles were incubated anaerobically at 25 degrees C for 10 months. Main Table 1 gives acetate 47 mM, sulfate 22.3 mM, magnesium 50.7 mM, calcium 8.22 mM, ammonium 10.58 mM and phosphate 0.89 mM, with 7.2 mM NaHCO3 and 1 mL/L Wolf vitamin solution. Magnesium was supplied as MgCl2.6H2O and phosphate as Na2HPO4. Initial pH was adjusted to give 7.5 after autoclaving; endpoint pH was 8.3 in both acetate cultures versus 7.7 and 7.9 in sterile counterparts. Vitamins were filter-sterilized and added after cooling. Solids were filtered, dried overnight at 30 degrees C in nitrogen and analyzed within a week.
The living strain is called Desulfovibrio alaskensis G20 in Han et al.; NCBI now resolves it as Oleidesulfovibrio alaskensis G20. Each 120-mL serum bottle contained 100 mL synthetic medium and an iron finishing nail, with a one-hour sterile hydrogen purge and butyl-rubber closure. Two drops of fresh G20 culture were added per inoculated bottle; drop volume and cell density were not specified. Duplicate inoculated and duplicate uninoculated bottles were incubated anaerobically at 25 degrees C for 10 months. Main Table 1 gives acetate 47 mM, sulfate 22.3 mM, magnesium 50.7 mM, calcium 8.22 mM, ammonium 10.58 mM and phosphate 0.89 mM, with 7.2 mM NaHCO3 and 1 mL/L Wolf vitamin solution. Magnesium was supplied as MgCl2.6H2O and phosphate as Na2HPO4. Initial pH was adjusted to give 7.5 after autoclaving; endpoint pH was 8.3 in both acetate cultures versus 7.7 and 7.9 in sterile counterparts. Vitamins were filter-sterilized and added after cooling. Solids were filtered, dried overnight at 30 degrees C in nitrogen and analyzed within a week.
Curated Evidence Points:
Support
Source:
han_2016
Author-manuscript PDF pages 3-5 and 7, Sections 2.1-2.3 and 3.2, Table 2 and Figure 1c-d document the medium, duplicate cultures, sterile controls and XRD assignments. Rietveld fits assign barićite 30.6 and 27.8 wt% of the reported mineral assemblages in samples 1_103 and 2_35, respectively, with other phases and reported zero amorphous contribution in these fits. These are fitted phase proportions, with rounding and no confidence intervals, not magnesium/phosphorus recovery percentages or a pure-product yield.
Partial
Source:
han_2016
All media already contained trace white solids before incubation. Black material formed on iron nails only in inoculated bottles, consistent with sulfide formation, but sulfate and sulfide concentrations were not measured. Growth, dissolved inorganic carbon and phosphate depletion also were not measured. Matched-pH or cell-free metabolite controls were not presented. The iron nail is a reactive experimental component; its contribution to dissolved iron and phase composition was not independently resolved. SEM observations for acetate-derived phosphate crystals are stated as data not shown and not further characterized, so no independent crystal-specific Mg/Fe analysis is inferred.
Partial
Source:
han_2016
Main Table 2 and SI Figure 1 show similar magnesium depletion in inoculated and sterile acetate media, so this experiment does not establish a microbial advantage in net magnesium removal. Total alkalinity was measured for only one endpoint bottle per acetate condition. No isolated phase-specific mass balance, purification yield, fertilizer performance, natural cold-seep production or industrial deployment is established.
Partial
Source:
han_2016
SI Table 1 uses phosphate 0.089 mM whereas main Table 1 gives 0.89 mM; it also differs in iron and formate-medium sodium inputs. The SI model therefore cannot be treated as an exact independent reproduction of the stated recipe. Figure 1 calls the co-occurring decahydrate Mg2(PO4)3.10H2O whereas Table 2 and Results use Mg3(PO4)2.10H2O. These internal inconsistencies are retained without silently correcting the source or naming the decahydrate as a separate verified mineral. Model saturation predictions are not measured phase occurrence or proof of biochemical causation.
Context_only
Source:
rivadeneyra_2014
An earlier, different wastewater-isolate agar study assigns baricite and bobierrite to recovered spherulites, but Figure 5 instead labels the companion phosphate as Mg3(PO4)2.2H2O. Boiling-water extraction and lack of a strain-to-phase map further limit that observation. It is not an independent replication of the G20 hydrogen/acetate system and does not resolve the present phase-composition uncertainty.
Sources & References
-
ima_2026_09: IMA-CNMNC. The New IMA List of Minerals, September 2026. Pages 1-2 definitions and terms; barićite page 20, bobierrite page 27. Retained official original re-inspected on 14 October 2026.
https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-14) -
han_2016: Han et al. (2016). Mineral formation during bacterial sulfate reduction in the presence of different electron donors and carbon sources. Chemical Geology 435:49-59. DOI 10.1016/j.chemgeo.2016.04.022. Complete ScholarWorks author manuscript, Sections 2-4, Tables 1-3, Figures 1-3; six publisher supplements (SI Tables 1-3 and Figures 1-3).
https://doi.org/10.1016/j.chemgeo.2016.04.022 (accessed 2026-10-14) -
ncbi_g20: NCBI Taxonomy 207559, Oleidesulfovibrio alaskensis G20. Live taxonomy XML verifies strain rank, parent species 58180 and equivalent name Desulfovibrio alaskensis G20 on 14 October 2026.
https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=207559&mode=Info (accessed 2026-10-14) -
rivadeneyra_2014: Rivadeneyra et al. (2014). Precipitation of Phosphate Minerals by Microorganisms Isolated from a Fixed-Biofilm Reactor Used for the Treatment of Domestic Wastewater. International Journal of Environmental Research and Public Health 11:3689-3704. DOI 10.3390/ijerph110403689; Sections 2.3-2.8, Tables 2-3 and Figures 4-5. Complete publisher PDF and PMC4025044 XML inspected.
https://doi.org/10.3390/ijerph110403689 (accessed 2026-10-14)
Curation History
| Timestamp | Curator | Action | Summary |
|---|---|---|---|
2026-10-14T08:16:55.696577+00:00 |
codex (GPT-6; codex) | CREATE | Created distinct phosphate mineral identity and qualified primary culture-phase assignments; retained processing, control, taxonomic and source consistency limits. |
Record source: data/records/baricite.yaml