• Chemistry: Pb2Cu(AsO4)(SO4)OH , Lead Copper Arsenate Sulfate Hydroxide
  • Class: Phosphates
  • Subclass: Arsenates
  • Uses: only as a mineral specimen.
  • Specimens

Arsentsumebite forms good, colorful specimens and is a popular collection mineral, although quite rare. It is closely related to its cousin, tsumebite. The two minerals are in a series in which the arsenate ion group in arsentsumebite is replaced by a phosphate ion group in tsumebite. The two differ only slightly; this is mostly because the structure is the same in the two minerals. Both are formed in the oxidation zone of lead-copper ore deposits.

Both minerals are unusual in that they have two ion groups instead of the usual one in most minerals. It the case of arsentsumebite, it has an arsenate ion group and a sulfate ion group. Mineralogists prefer to classify it as a phosphate (where arsenates are placed) because the arsenate ion group has a higher negative charge (-3) than the sulfate group (-2).


  • Color is green.
  • Luster is vitreous.
  • Transparency crystals are transparent to translucent.
  • Crystal System is monoclinic.
  • Crystal Habits include tabular crystals that can form twinned trillings and also as crusts.
  • Cleavage: None.
  • Fracture: Uneven.
  • Hardness is 3
  • Specific Gravity is approximately 6.4 (heavy for translucent minerals)
  • Streak is green.
  • Associated Minerals include azurite, cerussite and smithsonite.
  • Notable Occurrences are limited to Tsumeb, Namibia and a few other sites.
  • Best Field Indicators are crystal habit, locality, associations, density and color.
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ARSENTSUMEBITE specimen are-1
$ 75.00
Dims: 2.2x1.4x0.9" (5.7x3.7x2.3 cm)
Wt: 2.24 oz. (63.4g)
Tsumeb Mine, Tsumeb, Namibia
This specimen likely consists of mostly anglesite by weight, including several large transparent or milky white crystals. The Arsentsumebite is everthing green on this specimen. Part of it is in the form of green crusts on the surface of the specimen, part of it is in massive form exposed on the broken edges of the specimen, and part of it is in the form of inclusions in the anglesite crystals. None of the arsentsumebite shows any crystal form, even under a loupe. The crusts and inclusions are a darker green than the massive form, except for some dark green veins running through some of the larger chunks.
no photo
are-1 ($ 75.00)
Tsumeb Mine, Tsumeb, Namibia


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