Scholzite
Scholzite, CaZn2(PO4)2·2H2O: orthorhombic, hardness 3–4, density 3.11–3.13, 32.95% zinc, fine at Reaphook Hill, Australia, with its dimorph parascholzite.
Scholzite is a hydrated calcium zinc phosphate, CaZn2(PO4)2(H2O)2 on the September 2026 IMA list: orthorhombic, colourless to white, hardness 3 to 4, density 3.11 to 3.13, in crystals to 2.5 cm. Worked from the formula it is 32.95% zinc. Its Handbook sheet names fine examples from Reaphook Hill, South Australia, and Hagendorf, Bavaria, and a monoclinic twin, parascholzite.
In short
- The species. The September 2026 IMA-CNMNC Master List lists scholzite as CaZn2(PO4)2(H2O)2, status G, 1948, Germany. The Handbook of Mineralogy sheet writes CaZn2(PO4)2·2H2O: orthorhombic, crystals elongated along [001] to 2.5 cm, often in radial aggregates, cleavage fair on {100}, hardness 3 to 4, density 3.11 to 3.13, colourless to white or pale grey, streak white, vitreous. A 20.00 g piece reads 13.57 to 13.61 g in water.
- Australia. The Distribution field names “fine examples on Reaphook Hill, near Blinman, Flinders Ranges, South Australia” and Broken Hill, New South Wales. The sheet’s X-ray powder pattern is from Reaphook Hill, and its associates there are parahopeite and collinsite. It marks no type locality; the IMA list gives Germany, and Hagendorf, Bavaria, opens the Distribution list.
- Parascholzite, the dimorph. A script over the IMA list finds two rows with the identical formula CaZn2(PO4)2(H2O)2: scholzite (G, 1948) and parascholzite (A, 1980-056, Germany). The parascholzite sheet, fetched 12 November 2026, gives monoclinic C2/c or Cc, hardness about 4, density 3.12, and crystals “commonly twinned and intergrown with scholzite”.
- The Hagendorf recast. Recast on standard atomic weights, scholzite’s Hagendorf analysis gives Ca 1.00, Zn 1.72, Mg 0.09, Mn 0.08, Fe 0.02, PO4 1.99 and 2.26 H2O on a calcium basis, as printed. Parascholzite’s reproduces only on a 3-cation basis: Ca 0.92 and Mn 0.08 together, Zn 1.98, PO4 2.02, 1.97 H2O. The two sheets put manganese on opposite sides of the formula.
- Documented failure: weight and powder lines. Scholzite reads 13.57 to 13.61 g in water and parascholzite 13.59 g, so weight cannot split them. Both printed powder patterns open with 8.55 (100) and 2.805 or 2.804; their cells hold 211.9 to 213.4 and 212.2 cubic ångströms per formula unit. On these sheets, the crystal system, not the hand, separates them.
| Row | Basis of the recast | Ca | Zn | Mg + Mn + Fe | PO4 | H2O | Printed formula on the sheet | Density printed; from cell | 20.00 g in water |
|---|---|---|---|---|---|---|---|---|---|
| Ideal CaZn2(PO4)2·2H2O | Formula | 1 | 2 | 0 | 2 | 2 | Ideal column (2): ZnO 41.02, CaO 14.13, P2O5 35.77, H2O 9.08 | — | — |
| Scholzite (1), Hagendorf; total 99.90 with 0.88 insol. | Ca = 1 | 1.000 | 1.722 | 0.092 + 0.075 + 0.021 (Σ with Zn 1.909) | 1.99 | 2.26 | Ca1.00(Zn1.72Mg0.09Mn0.08Fe0.02)Σ=1.91(PO4)1.99·2.26H2O: reproduces | 3.11–3.13 meas., 3.10 calc.; 3.088–3.110 | 13.57–13.61 g |
| Scholzite (1), same analysis | 2 P | 1.005 | 1.730 | 0.092 + 0.076 + 0.021 | 2 | 2.27 | Zinc site 1.92 of 2: short | — | — |
| Parascholzite (1), Hagendorf; microprobe, total 99.3 | 3 cations | 0.916 (+ Mn 0.079) | 1.977 (+ Fe 0.028) | Mn with Ca; Fe with Zn | 2.02 | 1.96 | (Ca0.92Mn0.08)Σ=1.00(Zn1.98Fe0.03)Σ=2.01(PO4)2.02·1.97H2O: reproduces | 3.12(3) meas., 3.10 calc.; 3.106 | 13.59 g |
| Parascholzite (1), same analysis | 2 P | 0.908 | 1.959 | 0.078 + 0.028 | 2 | 1.94 | Does not give the printed figures | — | — |
| Cells | Sheet | — | — | — | — | — | Scholzite Pbcm or Pbc21, Z = 12, V 2542.3–2560.8 ų; parascholzite C2/c or Cc, β 106°27′, Z = 4, V 848.7 ų | Per formula unit 211.9–213.4 against 212.2 ų | — |
What is scholzite? Its formula and IMA status
Scholzite is CaZn2(PO4)2(H2O)2 on the September 2026 IMA list, status G (grandfathered), 1948, with Germany as the country of first description; the list’s first reference is Fortschritte der Mineralogie 27 (1948), 31. The Handbook of Mineralogy scholzite sheet writes CaZn2(PO4)2·2H2O, the same formula with the water written differently. Worked on standard atomic weights the formula mass is 396.81, and the mineral is 32.95% zinc, 10.10% calcium and 15.61% phosphorus by mass; as oxides, ZnO 41.02, CaO 14.13, P2O5 35.77 and H2O 9.08, which is the sheet’s ideal column to the hundredth.
What the sheet records. Orthorhombic, point group 2/m 2/m 2/m or mm2, space group Pbcm or Pbc21. Crystals are elongated parallel to [001], may be platy or pseudohexagonal, to 2.5 cm; they are typically intergrown with parascholzite on {100}, and form radial aggregates. Cleavage on {100} is fair, “a parting with parascholzite lamellae”. Hardness 3 to 4; density 3.11 to 3.13 measured, 3.10 calculated. Colourless to white or pale grey, rarely lime-green, reddish brown or yellow; streak white; lustre vitreous. Biaxial (+), α 1.581 to 1.585, β 1.586 to 1.587, γ 1.596 to 1.599.
Where it forms. “May be a primary mineral, but more commonly a secondary mineral in Zn phosphate-bearing granite pegmatites and sediments.” Its associates are given by locality: parascholzite, sphalerite and triplite at Hagendorf; parahopeite and collinsite at Reaphook Hill; tarbuttite at Kabwe. The other zinc phosphates on this site are hopeite and phosphophyllite; the hopeite page already records that the scholzite sheet prints rarely lime-green.
Is scholzite found in Australia? Reaphook Hill and Broken Hill
Yes, on the sheet. The Distribution field reads, in Australia, “fine examples on Reaphook Hill, near Blinman, Flinders Ranges, South Australia; from Broken Hill, New South Wales.” The sheet’s X-ray powder pattern is also from Reaphook Hill, with its strongest lines at 8.55 (100), 2.805 (70) and 4.300 (60). The parascholzite sheet names Reaphook Hill too.
The full list, as printed. From Hagendorf, Bavaria, Germany. At Otov, near Domažlice, Czech Republic. In the Baccu Locci mine, Sardinia, Italy. From Richelle, near Visé, Belgium. At Kabwe (Broken Hill), Zambia, a different Broken Hill from the Australian one. In the Tip Top mine, near Custer, South Dakota, and the Snowstorm mine, North Battle Mountain district, Nevada, USA. In China, at an undefined locality in Guangdong Province.
No type locality claimed. The sheet marks none, and the IMA list gives only the country, Germany. Hagendorf heads the Distribution list and supplies both sheets’ analyses, but this page does not call it the type locality; the term is explained at what is a type locality. Type material is at The Natural History Museum, London (1961,14), Harvard University (102210) and the National Museum of Natural History, Washington (106411).
Scholzite or parascholzite? The Hagendorf recast
One formula, two structures. The parascholzite sheet gives monoclinic, point group 2/m or m, space group C2/c or Cc, crystals flattened on {100} to 2 cm, “commonly twinned and intergrown with scholzite”, with polysynthetic twinning. Its name is “From the Greek para, for near, and its dimorphous relation to scholzite.” The IMA list gives it status A, 1980-056, Germany, first reference American Mineralogist 66 (1981), 843.
Method. Each oxide on each sheet was divided by its formula weight and the cations compared with the printed formula. Scholzite’s analysis reproduces its printed Ca1.00(Zn1.72Mg0.09Mn0.08Fe0.02)Σ=1.91(PO4)1.99·2.26H2O when calcium is set to 1. Parascholzite’s reproduces (Ca0.92Mn0.08)Σ=1.00(Zn1.98Fe0.03)Σ=2.01(PO4)2.02·1.97H2O only when the cations are set to 3. Set to 2 phosphorus instead, the scholzite zinc site holds 1.92 and the parascholzite calcium 0.91.
Documented failure: two sheets, two bookkeepings. The scholzite sheet files manganese with zinc; the parascholzite sheet files it with calcium. Neither says why, and on a 1.36 to 1.4% MnO analysis that choice moves the site totals by about 0.08. The scholzite analysis is also zinc-short and water-rich against the ideal, with 0.88% insolubles. The arithmetic is reported; the sheets are not corrected.
Can you tell scholzite from parascholzite in the hand?
Not on the sheets’ numbers. Densities are 3.11 to 3.13 against 3.12, which is 13.57 to 13.61 g against 13.59 g in water for a 20.00 g piece, on the method at how to measure specific gravity at home. Hardness is 3 to 4 against about 4; both are white-streaked and vitreous. Both cells hold about the same volume per formula unit, 211.9 to 213.4 against 212.2 cubic ångströms, and both reproduce the printed calculated density of 3.10 (3.088 to 3.110 and 3.106).
Even the powder lines coincide. The scholzite pattern opens 8.55 (100), 2.805 (70); the parascholzite pattern 8.55 (100), 2.804 (80), and both list 4.53 (30) and 3.404 or 3.406 (40). The optics differ slightly (parascholzite α 1.587, β 1.588, γ 1.603, 2V 25°), and the parascholzite sheet records polysynthetic twins. Because the scholzite sheet says the two are typically intergrown on {100}, a label reading only “scholzite” may hold both.
Elsewhere on this site. The zinc sulfide that the sheet names at Hagendorf is on sphalerite, and other phosphates are in the species index. We hold no catalogue and nothing here is offered for sale; the wanted list is the only commercial route.