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Woodhouseite mineral

Woodhouseite is the calcium aluminium sulfate-phosphate mineral CaAl3(SO4)(PO4)(OH)6, distinct from strontium-dominant svanbergite, calcium aluminium phosphate crandallite and calcium as an element. The September 2026 IMA list records its redefinition by special procedure in 1987. Lemmon (1937) described natural crystals from quartz veins adjoining and penetrating andalusite deposits on White Mountain, Mono County, California. Geometrical crystallography, optical observations and wet chemical analysis of hand-sorted crystals supported the new mineral. Its analysis contains minor substituents and a phosphate-sulfate imbalance; Lemmon explicitly considered a single analysis insufficient to prove the proposed substitution. This historical description is not a modern single-crystal refinement. Stoffregen and Alpers (1987) subsequently measured natural aluminium phosphate-sulfate grains by electron microprobe at Summitville, La Granja and La Escondida. Calcium-rich grains approaching woodhouseite occur at depth in Summitville and at La Granja, where small grains appear to replace apatite and contact pyrophyllite. Variable Ca/Sr and phosphate/sulfate ratios, minor additional cations and calculated rather than measured water distinguish these grains from pure ideal endmembers. Figure 1 depicts an approximately equal Ca/Sr grain, not pure woodhouseite. Apatite dissolution or replacement during advanced argillic alteration is the authors' field-textural interpretation; there was no controlled formation experiment, reaction time series or microbial assay. Their 250 degrees C, 40-bar stability diagram uses assumed aqueous compositions and an inferred woodhouseite boundary because direct thermodynamic data were unavailable to that study. It is not a measured formation threshold, and its hydroxyapatite model omits fluoride/chloride effects. The companion svanbergite record uses the same field study. These sources establish mineral identity and qualified natural alteration context, not microbial formation, elemental extraction yield, isolated-product recovery or industrial deployment. No constituent-element criticality is inherited.

Sources & References

  1. ima_2026_09: IMA-CNMNC. The New IMA List of Minerals, September 2026. Definitions PDF page 1; Svanbergite page 209 and Woodhouseite page 236, both redefined (Rd), 1987 special procedure. Freshly acquired authority bytes match the previously retained September edition.
    https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-15)
  2. handbook_woodhouseite: Handbook of Mineralogy, Woodhouseite. Complete one-page entry, version 1, copyright 2001-2005. Ideal composition, natural crystal and diffraction data; secondary identity context.
    https://www.handbookofmineralogy.org/pdfs/woodhouseite.pdf (accessed 2026-10-15)
  3. lemmon1937: Lemmon DM (1937). Woodhouseite, a new mineral of the beudantite group. American Mineralogist 22(9):939-948. Complete ten-page original; physical properties and geometrical crystallography pages 939-942, Table 1 and Figures 1-4; chemical preparation and Table 2 pages 942-943; occurrence pages 943-944.
    https://msaweb.org/AmMin/AM22/AM22_939.pdf (accessed 2026-10-15)
  4. stoffregen_alpers1987: Stoffregen RE and Alpers CN (1987). Woodhouseite and svanbergite in hydrothermal ore deposits: products of apatite destruction during advanced argillic alteration. Canadian Mineralogist 25:201-211. Complete eleven-page original; occurrences pages 203-205, analytical methods and Table 3 page 205, Figures 1-3 pages 204/206/207, and paragenetic interpretation page 208. This is the same field-study lineage in the companion mineral record, not independent replication.
    https://www.rruff.net/doclib/cm/vol25/CM25_201.pdf (accessed 2026-10-15)

Curation History

Timestamp Curator Action Summary
2026-10-15T09:31:36.803516Z codex (GPT-6; codex) CREATE Added a primary-supported mineral identity and bounded natural alteration context, preserving field inference, compositional uncertainty and shared-study lineage without asserting a microbial mechanism or inherited criticality.

Record source: data/records/woodhouseite.yaml