Bindheimite
Bindheimite, Pb2Sb2O6(O,OH), is listed by the IMA as Q, questionable, since 2013; not discredited. Yellow earthy crusts on oxidised lead-antimony ore.
Bindheimite is a lead antimonate, Pb2Sb2O6(O,OH) in the Handbook, that the September 2026 IMA list records with status Q, questionable, after a 2013 special procedure. It is not discredited: in 2013 its status was changed from discredited to questionable. It forms yellow to brown earthy crusts, hardness 4 to 4.5, in oxidised lead-antimony deposits.
In short
- The status is Q, and Q means questionable. The September 2026 IMA-CNMNC Master List prints bindheimite as Pb2Sb5+2O7, Q, 2013 s.p., Russia. The list defines Q as applying to poorly characterized minerals, whose validity could be doubtful. That is not discredited, and a bindheimite label is not wrong, only unconfirmed.
- It was discredited once, and the ruling was reversed. Christy and Atencio’s 2013 clarification changed bindheimite, stibiconite and five other names from ‘discredited’ to ‘questionable’ pending further research. Stibiconite carries the same Q, 2013 s.p. on the list.
- The IMA formula has the same stoichiometry as oxyplumboroméite, Pb2Sb2O7, an approved species (IMA 2013-042, Harstigen mine, Sweden). The same formula does not make them the same mineral: a bindheimite specimen can be renamed only on an analysis.
- Worked composition: Pb2Sb2O7 is 57.98% PbO and 42.02% Sb2O5, and 53.82% lead by mass. With one H2O it gives 56.65%, 41.06% and 2.29%, which reproduces the sheet’s ideal column exactly. The sheet’s measured density runs 4.6 to 8.4, the top 1.83 times the bottom.
- Two British entries are on the sheet: the Bodannon mine and Wheal Boys, St. Endellion, and elsewhere in Cornwall; and Caldbeck Fells, Cumbria. None of the 176 sheets in this site’s reference set mentions bindheimite; stibiconite appears on one, as an associate of stibnite.
| Name | Formula | IMA status, number or year, country | Hardness | Density | Colour | Pb by mass (ideal) |
|---|---|---|---|---|---|---|
| Bindheimite (Handbook) | Pb2Sb2O6(O,OH) | Q; 2013 s.p.; Russia | 4 to 4.5 | 4.6 to 8.4 meas.; [6.78 to 6.88] calc. | Yellow, yellow-brown, brown, white, grey, greenish | 53.82% as Pb2Sb2O7 |
| Bindheimite (IMA) | Pb2Sb5+2O7 | Q; 2013 s.p.; Russia | — | — | — | 53.82% |
| Oxyplumboroméite | Pb2Sb2O7 | A; 2013-042; Sweden | about 5 | 6.732 calc. | Yellow to brownish yellow | 53.82%; type material Pb0.92 with Ca0.87 at A |
| Stibiconite | Sb3+Sb5+2O6(OH) | Q; 2013 s.p.; Germany | Not quoted (no sheet cached) | Not quoted | — | 0% |
| Cerussite (an associate) | PbCO3 | G; 1845; Italy | 3 to 3.5 | 6.55 | Colourless, white, pale yellow, grey, black | 77.54% |
Is bindheimite discredited? No: the IMA list says questionable
Read the row exactly. The September 2026 IMA list prints Bindheimite, Pb2Sb5+2O7, Q, 2013 s.p., Russia. The first reference is A System of Mineralogy, 5th ed. Wiley, New York (1868), 591. The list’s own legend defines the letter: Q = questionable (it applies to poorly characterized minerals, whose validity could be doubtful). It also explains s.p. as the year in which a special procedure, a redefinition or renaming, was approved.
Why the date is 2013. Christy and Atencio’s 2013 letter in Mineralogical Magazine 77, 13–20, presented corrections to the 2010 pyrochlore-supergroup nomenclature report. It changed the status of bindheimite, bismutostibiconite, jixianite, monimolite, partzite, stetefeldtite and stibiconite from ‘discredited’ to ‘questionable’ pending further research. A label or reference that calls bindheimite discredited is out of date against the current list.
So the name stays on the label, with its status. Bindheimite (IMA status Q) is accurate. Relabelling a specimen as a different species needs an analysis, and the reason is set out below. The general form is on how to label and catalogue a mineral collection.
Bindheimite or oxyplumboroméite? Same formula, different status
On paper they match. The IMA writes bindheimite Pb2Sb5+2O7 and oxyplumboroméite Pb2Sb2O7, two lead, two antimony, seven oxygen. Oxyplumboroméite was approved in 2013 (IMA 2013-042) as a new mineral of the roméite group of the pyrochlore supergroup. The Handbook puts bindheimite in the stibiconite group, and its sheet predates that nomenclature.
Three things keep them apart on the evidence available.
- Setting. Oxyplumboroméite’s type material is from fissure fillings in tephroite skarn at the Harstigen mine, Värmland, with calcite and leucophoenicite. The Handbook puts bindheimite in the oxidized portions of antimony-bearing lead deposits, with galena, cerussite and jamesonite.
- Chemistry of the type material. The 2013 description gives an A site of Pb0.92 with Ca0.87, nearly as much calcium as lead, and B of Sb1.73 Fe3+0.27. It is described as the Pb analogue of oxycalcioroméite.
- Characterisation. Oxyplumboroméite has a refined crystal structure. Bindheimite’s Q means its characterisation is not yet good enough to say.
No source we fetched says bindheimite material is oxyplumboroméite, so this page does not say so. What can be said is that a lead-dominant, oxygen-dominant roméite-group analysis would today be named oxyplumboroméite.
What the bindheimite sheet's own numbers show
The ideal composition, worked. On standard atomic weights Pb2Sb2O7 has a formula mass of 769.91: PbO 57.98%, Sb2O5 42.02%, or 53.82% lead and 31.63% antimony by mass. The sheet’s third column is Pb2Sb2O7·H2O. Adding one water gives a formula mass of 787.93, and PbO 56.65%, Sb2O5 41.06% and H2O 2.29%, identical to the printed column.
The real analyses do not sit on it. Converting the oxides to atoms, the Wamsley mine, Nevada, analysis (PbO 44.12%, Sb2O5 40.35%) gives Pb/Sb of 0.792 against the ideal 1.000. It also carries 5.22% Fe2O3 and 3.63% insoluble matter. The Otjimboyo East, Namibia, analysis gives 0.993, but with 9.7% Bi2O3 and 8.0% insoluble. A 1960 reference on the sheet is titled A bismuth-bearing variety of bindheimite.
The density range is the clearest sign. Measured density runs from 4.6 to 8.4, a factor of 1.83, against a calculated 6.78 to 6.88. The sheet describes dense to earthy cryptocrystalline masses, fibrous perhaps due to pseudomorphism. That is a description of mixed, fine-grained material; see what is a pseudomorph. Density is not a reliable test for this name.
Where bindheimite is found, including Cornwall and Caldbeck
The Handbook calls it common in the oxidized portions of antimony-bearing lead deposits and a widely distributed mineral, but rarely in large amounts. That is the zone described on what is a gossan. Its associates are galena, pyrite, chalcopyrite, tetrahedrite, jamesonite, bournonite, zinkenite, cerussite, plumbojarosite, argentojarosite, minium, massicot, quartz, barite, calcite and dolomite. Among them are galena, cerussite, bournonite and tetrahedrite.
The distribution, in the sheet’s order: Nerchinsk, Siberia, Russia; Oberzeiring, Styria, and Hüttenberg, Carinthia, Austria; Camerata Cornello and Gorno, Lombardy, Italy; the Bodannon mine and Wheal Boys, St. Endellion, and elsewhere in Cornwall, and Caldbeck Fells, Cumbria; Otjimboyo East, Karibib, Namibia; Hamman N’bail, Algeria; Broken Hill, New South Wales; the Chichibu mine, Japan; Machacamaraca, Bolivia; the Ojuela mine, Mapimí, Durango, Mexico; and, in the USA, the Montezuma and other mines, Arabia district, Nevada, the Coeur d’Alene district, Idaho, Tintic and the Horn Silver mine, Utah, and Cerro Gordo, California.
Against the 176 sheets in the set (case-insensitive search of the full text): bindheimite appears on none. Stibiconite, its Handbook group name, appears on one, the association line of stibnite. This page gives no handling or health advice. The lead and antimony figures above are composition, not exposure. See toxic minerals in a collection, the HSE EH40 workplace exposure limits, COSHH 2002 or a clinician. The rest of the reference section is at the species index. We hold no catalogue and nothing here is offered for sale; the wanted list is the only commercial route.