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Goldmanite mineral

Goldmanite is the calcium-vanadium garnet mineral with ideal formula Ca3V3+2(SiO4)3, status A and approval 1963-003 in the September 2026 IMA list. It is distinct from elemental vanadium, generic vanadium-bearing garnet and mixed uranium-vanadium ore. Moench and Meyrowitz described fine natural grains from a prospect pit in the Sandy mine area, Laguna district, New Mexico. The chemically analyzed separate was a substituted garnet, calculated as 59.8 mole percent goldmanite endmember with grossular, andradite, pyrope and spessartite components; this is a composition calculation, not a phase fraction or recovery yield. Its total vanadium was reported as V2O3, but the authors explicitly could not determine vanadium and iron valences chemically and inferred trivalence from crystal chemistry. Earlier unusually high vanadium assays may have included spinel contamination. The ideal species formula therefore does not describe every natural grain as a pure endmember. Abiotic laboratory syntheses are documented below. No criticality designation is inherited from vanadium, and these studies do not establish microbial extraction or industrial recovery.

Microbial & Biochemical Mechanisms (2)

Hydrothermal crystallization from chemically prepared gels

other

Ito obtained products with powder-diffraction lines assigned to goldmanite from chemically prepared calcium-vanadium-silicate mixtures. Table 2 run 6, using the nominal goldmanite composition and added ascorbic acid, lists goldmanite as the only identified crystalline product after 24 hours at 760 degrees C and 15,000 psi. Other recipes produced mixed phases or no assigned goldmanite. This is abiotic laboratory synthesis from reagents, without a quantified phase-purity percentage, vanadium extraction balance or isolated-metal recovery.

Experimental Context & Analytical Limits:
Starting mixtures were co-precipitated gels prepared from C.P.-grade chemicals with vanadium initially in the V4+ form. Table 2 identifies the run 6 G-c precursor as precipitated with NH4OH and (NH4)2CO3 at the nominal goldmanite composition. The common method used electrically sealed gold tubing, 2-5 mm diameter, with no additional water because the precursors retained water; precursors were dried below 100 degrees C. Precise atmosphere control was explicitly impossible. Residual organic/reducing material and added ascorbic acid affected oxygen conditions; no measured oxygen fugacity, initial pH, replicate count or quantitative phase yield is supplied for run 6. Slightly alkaline residual liquid was reported only when liquid remained after some runs. Figure 3 shows synthetic isometric grains, but does not establish a run 6-specific size distribution. Table 5 diffraction concerns run 2 and Table 8 bulk valence analysis concerns run 5, not run 6. The haradaite and roscoelite arms of this same paper must not be transferred to this garnet.
Curated Evidence Points:
Support Source: ito1965
Pages 300-304 and Table 2 identify the preparation, actual run settings and X-ray-assigned products; run 6 is 760 degrees C, 15,000 psi, 24 hours, ascorbic acid, with goldmanite listed. Pages 304-310 and Table 5 compare a different synthetic run 2 with natural garnet powder patterns. This supports formation of a goldmanite-type crystalline product under specified laboratory conditions, not phase-pure or industrial recovery.
Partial Source: ito1965
Table 2 run 1 at 400 degrees C, 20,000 psi for 24 hours lists hydrated calcium silicate and VO2 without goldmanite; V-rich and Ca-rich runs contain quartz, vanadium oxides, cristobalite or wollastonite alongside goldmanite. Table 5 uses run 2, whose Table 2 product also contains quartz and V2O3. Table 8 analyzes run 5 and reports both V2O3 and VO2 equivalents; the authors attribute minor V4+ to oxide impurities rather than proving its absence from every garnet site. Bulk redox titration and diffraction on different runs do not establish run 6 site-specific valence or perfect purity. The proposed equilibrium/paragenetic relations on pages 313-315 were inferred from these products with uncontrolled atmosphere, not reversible equilibrium experiments.

Hydrothermal garnet synthesis from glass under a stated redox buffer

other

Strens separately reported hydrothermal preparation of calcium-vanadium garnet from glass at 530 degrees C and 3.0 kilobars for 30 days under the stated hematite-magnetite oxygen buffer. The dark-green equigranular product had a reported refractive index and cell edge consistent with a synthetic goldmanite endmember. This is a distinct abiotic laboratory experiment, not a repetition of Ito run 6 and not recovery from ore.

Experimental Context & Analytical Limits:
The starting glass had a Ca:V ratio of 3:2 and excess silica, intended to suppress hydroxyl substitution for silicate. The one-page note does not provide a full glass recipe, sample loading, water addition, apparatus, replication, complete diffraction pattern, direct valence measurement or phase-resolved mass accounting. The author reports theoretical yield without a measured mass denominator or uncertainty; no numerical recovery fraction is curated. The reported cell edge of 12.070 +/- 0.005 angstrom and refractive index of 1.834 +/- 0.003 are distinguished from properties extrapolated by correcting the composition of the natural Laguna specimen.
Curated Evidence Points:
Page 260 synthesis paragraph gives the glass Ca:V ratio, excess silica, 530 degrees C, 3.0 kilobars, 30-day duration and hematite-magnetite buffer, followed by product morphology, refractive index and cell edge. This independently supports a synthetic calcium-vanadium garnet product under that protocol.
The same short note calls the yield theoretical but gives no mass balance, phase-quantification method or measurement uncertainty for that claim. Its later refractive-index and cell-edge values corrected from natural mixed garnet are calculations, not additional synthetic measurements. No extraction, microbial effect or industrial deployment is tested.

Sources & References

  1. ima_2026_09: IMA-CNMNC. The New IMA List of Minerals, September 2026. Goldmanite row, PDF page 84: Ca3V3+2(SiO4)3, A, 1963-003; status definitions page 1.
    https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-15)
  2. moench1964: Moench RH, Meyrowitz R (1964). Goldmanite, a vanadium garnet from Laguna, New Mexico. American Mineralogist 49:644-655. Natural occurrence and separation pages 646-648; diffraction Table 1; chemistry Tables 3-4 and analytical methods pages 650-652; inferred valence and endmember calculation pages 652-653.
    https://msaweb.org/AmMin/AM49/AM49_644.pdf (accessed 2026-10-15)
  3. ito1965: Ito J (1965). Synthesis of vanadium silicates: haradaite, goldmanite and roscoelite. Mineralogical Journal 4(4):299-316. Full original; separate species-specific runs and characterization, not independent experiments for every citation of this paper.
    https://doi.org/10.2465/minerj1953.4.299 (accessed 2026-10-15)
  4. strens1965: Strens RGJ (1965). Synthesis and properties of calcium vanadium garnet (goldmanite). American Mineralogist 50:260. Complete one-page mineralogical note; synthesis paragraph and measured versus calculated physical properties.
    https://msaweb.org/AmMin/AM50/AM50_260.pdf (accessed 2026-10-15)

Curation History

Timestamp Curator Action Summary
2026-10-15T18:26:20.106756Z codex (GPT-6; codex) CREATE Prepared evidence-backed mineral identity and qualified abiotic synthesis, preserving specimen substitutions, run-specific characterization, mixed and null products, and limits on valence, atmosphere and yield.

Record source: data/records/goldmanite.yaml