Zaccagnaite

Where it forms, where it's found

Geological setting: Cavities in calcite veins in marble.
Type locality: Calagio quarries (Calagio Quarry
Olmo Quarry)
Colonnata quarrying basin
Carrara
Massa-Carrara Province
Tuscany
Italy
44.0837°, 10.1467°

9recorded occurrences

Source · OpenStreetMap

Physical

Lustre: Subvitreous
Transparency: Transparent
Colour: White to pale yellow
Streak: White
Cleavage: Perfect
Perfect on (0001)
Density: 2.84 g/cm³

Optical

Optical type: Uniaxial (-)
Luminescence: (not reported)

Crystallography

Crystal system: Hexagonal
Type-locality form: Minute hexagonal crystals < 0.2 mm long and 0.02-0.03 mm thick. These are covered by a thin crust of fraipontite and resemble so-called “Brugola” screws (i.e., set-screws).
Comment: see polytypes

Crystal structure

Chemical composition

Constituent elements: Mass composition breakdown
Element Atoms At. mass g/mol Mass g/mol Mass share
8OOxygen Oxygen 18 15.999 287.982
45.45%
30ZnZinc Zinc 4 65.380 261.520
41.27%
13AlAluminium Aluminium 2 26.982 53.964
8.52%
1HHydrogen Hydrogen 18 1.008 18.144
2.86%
6CCarbon Carbon 1 12.011 12.011
1.90%
Total 633.621 100.00%
Mass share = atoms × atomic mass ÷ molar mass × 100
From IMA formula

Mass composition breakdown
Element	Atoms	At. mass g/mol	Mass g/mol	Mass share
8OOxygen	Oxygen	18	15.999	287.982	45.45%
30ZnZinc	Zinc	4	65.380	261.520	41.27%
13AlAluminium	Aluminium	2	26.982	53.964	8.52%
1HHydrogen	Hydrogen	18	1.008	18.144	2.86%
6CCarbon	Carbon	1	12.011	12.011	1.90%
	Total	633.621	100.00%

Synonyms

IMA1997-019

In other languages

German: IMA 1997-019 · Zaccagnait
Italian: Zaccagnaite
Chinese: 羟碳铝锌石

Classification

Strunz

10th ed.

5.DA.45

5CarbonatesClass
5.DCarbonates with additional anions, with H₂ODivision
5.DAWith medium-sized cationsGroup
5.DA.45ZaccagnaiteSpecies

Dana

8th ed.

16b.06.01.04

16bHydrated Carbonates Containing Hydroxyl or HalogenClass
16b.06A_mB_n(XO₃)_pZ_qxH₂O & with (m+n):p = 8:1Type
16b.06.01Sjorgrenite-Hydrotalcite Group (Sojogrenite Subgroup:Hexagonal)Group
16b.06.01.04ZaccagnaiteSpecies

Group, growth & confusion

6 members

Literature, links & citation

Citations

2001Merlino, Stefano, Orlandi, Paolo (2001) Carraraite and zaccagnaite, two new minerals from the Carrara marble quarries: their chemical compositions, physical properties, and structural features. American Mineralogist, 86 (10) 1293-1301 doi:10.2138/am-2001-1017 DOI: 10.2138/am-2001-1017
2012Mills, S. J.; Christy, A. G.; Génin, J.-M. R.; Kameda, T.; Colombo, F. (2012) Nomenclature of the hydrotalcite supergroup: natural layered double hydroxides. Mineralogical Magazine, 76 (5). 1289-1336 doi:10.1180/minmag.2012.076.5.10DOI: 10.1180/minmag.2012.076.5.10
2021(2021) Zaccagnaite. Handbook of Mineralogy. Mineralogical Society of America

Cite this entry

@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Zaccagnaite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/zaccagnaite-10810},
  note      = {Accessed 2026-05-11}
}