Is galena toxic
Galena is PbS, 86.60% lead by mass, hardness 2.5 to 2.75, with perfect cubic cleavage. An intact crystal is the easy case. The fragments it sheds are not.
Galena is lead sulphide, PbS, and 86.60% lead by mass, the highest of the 19 lead species among the 176 mineral sheets in this site's reference set. An intact crystal handled with clean dry hands is the low-exposure case. What sets galena apart is perfect cubic cleavage at hardness 2.5 to 2.75: a knock can shed small lead-bearing cubes.
In short
- Yes, galena contains lead, and more of it than any other lead species in this site's reference set. PbS works out at 86.60% lead by mass, which is also the figure the Handbook of Mineralogy prints for pure PbS. Of the 19 species in this site's 176-sheet reference set that have lead in their formula, galena is the highest; mendipite is next at 85.80%.
- Toxic is the wrong word to hang the decision on; route is the right one. Lead matters when it is swallowed or breathed in as particles. A solid crystal on a shelf does neither. The three-state test set out on the malachite page — solid, worked, friable — applies here, and this page does not repeat it; galena changes only how the first state behaves.
- Galena's distinctive problem is that its solid state leaks into its friable state. Five of the 19 lead species record a perfect cleavage, and galena's is the only one of the five that runs in three directions. So a knock does not chip it; it releases cubes, and the cubes cleave again into smaller cubes and glittering grit.
- Check the bottom of the box, not just the specimen. Loose bright metallic grit under a galena is galena, at 86.60% lead. Damp-wipe it out, do not blow it, and keep the specimen padded so it cannot rattle.
- Nothing on this page is health, safety or legal advice. In the UK, work with lead is governed by the Control of Lead at Work Regulations 2002, and COSHH regulation 5 says COSHH does not apply where those regulations do. Anything about symptoms or exposure belongs with a clinician.
| Species | Formula | Lead by mass | Hardness | Cleavage as recorded | Density |
|---|---|---|---|---|---|
| Galena | PbS | 86.60% | 2.5 to 2.75 | Perfect on {001}; parting or cleavage on {111} | 7.58 |
| Mendipite | Pb3O2Cl2 | 85.80% | 2.5 | Perfect on {010}; {100} less perfect | 7.240 |
| Cerussite | PbCO3 | 77.54% | 3 to 3.5 | Good on {110} and {021} | 6.55 |
| Pyromorphite | Pb5(PO4)3Cl | 76.38% | 3.5 to 4 | Interrupted | 7.04 |
| Chloroxiphite | Pb3CuO2Cl2(OH)2 | 75.62% | 2.5 | Perfect on {101}; distinct on {100} | 6.76 to 6.93 |
| Vanadinite | Pb5(VO4)3Cl | 73.15% | 2.5 to 3 | None | 6.88 |
| Anglesite | PbSO4 | 68.33% | 2.5 to 3 | Good on {001} | 6.38 |
| Diaboleite | Pb2CuCl2(OH)4 | 67.18% | 2.5 | Perfect on {001} | 5.42 |
| Wulfenite | PbMoO4 | 56.44% | 2.75 to 3 | Distinct on {011} | 6.5 to 7.5 |
| Corkite | PbFe3(PO4)(SO4)(OH)6 | 31.03% | 3.5 to 4.5 | Perfect on {0001} | 4.295 |
Does galena contain lead? 86.60%, and how the number is made
Method. Lead by mass is arithmetic on the ideal formula with standard atomic weights: lead 207.2, sulphur 32.06. PbS has a formula mass of 239.26, of which lead is 207.2, giving 86.60%. The Handbook of Mineralogy sheet for galena prints an analysis column for pure PbS reading Pb 86.60 and S 13.40, so the calculation and the reference agree to the second decimal.
The survey. Of the 176 Handbook sheets in this site's reference set, converted with pdftotext and searched by script, 19 carry lead as an essential constituent: 17 found from the formula line and two, corkite and diaboleite, whose formula line did not survive text extraction and were confirmed from the analysis table by hand. Their lead contents run from 29.11% in beudantite to 86.60% in galena. Galena is the highest of the 19, and mendipite, at 85.80%, is the only other within a point of it; cerussite is next at 77.54%. The table above shows ten of the 19, chosen to include all five with a perfect cleavage.
The sheet's own summary is blunter: galena is the most important ore mineral of lead. The British localities in its distribution list are Alston Moor in Cumbria and Wanlockhead in Dumfries, and its analysis column includes the Barrow mine at Newlands, Cumbria. The lead content is not in doubt, and it is not the variable that decides what to do.
Is galena toxic to touch? Where it sits in the three-state test
The malachite page introduced a three-state test for any mineral carrying a hazardous element: a solid specimen, a worked object, and a friable or deteriorating one. The question it asks is what would have to happen for any of the material to reach you. Applied to galena, two of the three states behave as they do for malachite and one does not.
Worked: galena is rarely cut or polished, and the working it does get — trimming, crushing, cleaning with abrasives — is precisely the dust-making case. Friable: the Handbook records galena as cleavable masses, coarse to very fine granular, and fine-grained granular galena crumbles in a way a coarse crystal does not. Both are covered by the malachite page's reasoning without change.
Solid is where galena is different. For malachite, the solid state is stable; you can leave it alone and it stays solid. A galena crystal is solid until it is knocked, and then it is solid plus a scatter of smaller solids. Holding one with clean dry hands and washing afterwards is the ordinary low-exposure case. Dropping one, rattling it in a box or picking at a damaged corner moves part of it straight into the friable state. The wider lead group is on toxic minerals in a collection.
Why galena's cubic cleavage is the whole difference
Five of the 19 lead species in the set record a perfect cleavage: galena, mendipite, chloroxiphite, diaboleite and corkite. Galena is cubic, so its perfect cleavage on {001} is three equivalent planes at right angles; the other four each break along a single perfect plane. Galena is the only lead species in this site's reference set whose perfect cleavage runs in three directions, and that is what turns a knock into a handful of small cubes rather than a chip.
Three properties make it worse together. Hardness 2.5 to 2.75 puts galena below calcite at 3, so it is abraded by the quartz and calcite the Handbook lists among its associates. Density 7.58 means a dropped specimen lands hard, and a heavy piece shifting in a drawer puts real force on its own corners. And every fragment is itself a cleavage cube, which will cleave again: the process runs down to grit without changing character.
What that means in practice, and it costs attention rather than money. Give galena its own padded box so it cannot rattle against anything. Handle it by the matrix where there is matrix. After moving or photographing one, look at the base of the box: loose bright metallic grit under a galena is galena, and it is 86.60% lead. Damp-wipe it out rather than blowing it, and wash your hands. Cleaning methods that suit it are on how to clean mineral specimens; how to tell cleavage from fracture is on cleavage or fracture.
The rest of this section is indexed at the collecting guides. We hold no catalogue and nothing on this site is offered for sale; the wanted list sets out what we look for, and locality data is what makes a galena worth having at all.