• Chemistry: (Cu, Zn)2(AsO4)(OH), Copper Zinc Arsenate Hydroxide
  • Class: Phosphate Class
  • Subclass: Arsenates
  • Uses: Only as mineral specimens
  • Specimens

Cuproadamite is not always thought of as a separate mineral from its close cousin adamite. However it is increasingly being sold and distributed as cuproadamite, although it has yet to be officially acknowledged as a separate mineral. It contains an appreciable amount of copper and this usually colors the crystals a reddish purple to amethyst purple. Cuproadamite is an intermediate "mineral" between adamite - Zn2AsO4(OH) and olivenite - Cu2AsO4(OH).

Unfortunately for collectors who love fluorescent minerals(adamite is one of the best fluorescing minerals in the world), cuproadamite does not fluoresce at all. The copper acts as a "poison" for the fluorescence, making for a fairly reliable test to distinguish cuproadamite from adamite. The test is not foolproof however, as some adamites that contain little or no copper do not fluoresce either. Nearly all properties of cuproadamite are identical to adamite except typical color, density and fluorescence.


  • Color is typically reddish purple, but can be purple, red or even green.
  • Luster is adamantine.
  • Transparency crystals are transparent to translucent.
  • Crystal System is orthrombic; 2/m 2/m 2/m
  • Crystal Habits include diamond-shaped, wedge-like prisms sometimes modified with minor prismatic faces and terminated by a double triangle. Mostly in druses and radiating clusters that can form wheel and "wheat-sheath" shapes. Rarely in a perfectly smooth botryoidal habit like smithsonite, but commonly found with well-formed crystal terminations that sparkle on the top of the "sub-botryoidal" surface.
  • Cleavage is perfect in one direction.
  • Fracture is conchoidal.
  • Hardness is 3.5.
  • Specific Gravity is approximately 4.6 (heavy for translucent minerals and slightly heavier than adamite)
  • Streak is white.
  • Other Characteristics: does not fluoresces like its cousin adamite.
  • Associated Minerals are adamite, limonite, conichalcite, smithsonite, aragonite, calcite, and other oxidation zone minerals.
  • Notable Occurances include the famous mines at Mapimi, Mexico; also Greece and other sites that contain adamite and copper minerals.
  • Best Field Indicators are color, density, non-fluorescences, associations and crystal habits.
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CUPROADAMITE specimen cad-1
$ 63.00
Dims: 4" x 2-1/2" x 2-1/2"
Wt: 13.5 oz
Laurion, Greece
At first glance, one may think that this is a smithsonite specimen, with dozens of blue-green bulbous formations on a heavy hematite/goethite matrix. Closer examination will reveal that each "blob" is a small, radiating cluster of semitransparent Cuproadamite crystals. Each cluster averages 1/8 inch in diameter, and contains crystals that are much too large to produce the silky, "melted wax" sheen of smithsonite. In a few places, the clusters are packed closely enough to intersect, making small areas that are coated with crusts of the mineral. Their color is unusual and splendid, with the dark, rust-brown of the matrix adding the perfect backdrop. Do you have one of these??
no photo
cad-1 ($ 63.00)
Laurion, Greece
CUPROADAMITE specimen cad-2
$ 60.00
Dims: 1.8" x 1.3" x 1.1"(4.6 x 3.3 x 2.8 cm)
Wt: 1.54 oz.(43.8 g) w/ base
Tsumeb, Namibia
This particular specimen actually consists of two separate specimens! The above dimensions apply to the larger piece, and the weight represents both specimens and the bottom of a plastic specimen box. The first specimen consists of a small piece of what appears to be quartzite that is covered by a crust made up of both goethite and dolomite or calcite. There are a few very small moss-like Cuproadamite clusters made up of almost microscopic radiating needles. They have a bright green color, no luster, and seem to be opaque. There are also several patches of noncrystalline or massive Cuproadamite on the host rock. The other specimen has dimensions of 1.0 x 0.5 x 0.5"(2.5 x 1.3 x 1.3 cm) and is made up entirely of Cuproadamite crystals. They have the same bright green color, a pearly luster, and are translucent. They occur as flat blades with wedge-shaped terminations, several of which have small areas of near-transparence on their tips. The largest of these crystals measures 0.3 x 0.2 x 0.1"(8 x 4 x 1 mm) and rises up from the rest of the specimen, so as to be quite visible. Though there is substantial damage to the specimen, the crystals show good form and are much larger than those on the other specimen. Both pieces are attached to a specimen box's base with a removable putty.
no photo
cad-2 ($ 60.00)
Tsumeb, Namibia
CUPROADAMITE specimen cad-3
$ 35.00
Dims: 2.8" x 2.0" x 1.2"(7.1 x 5.1 x 3.0 cm)
Wt: 3.82 oz. (108.2 g)
Mina de Ojuela, Mapimi, Durango, Mexico
Three hemispherical clusters and a single crystal of Cuproadamite rest near or inside a crevice in the goethite/limonite host rock of this specimen- all are in excellent condition, showing no damage. The largest of the clusters measures 0.5" (1.3 cm) in diameter, and like one other cluster, has a good round, acicular form. The other cluster is wedged inside the crevice, which prevented a symmetrical growth. The individual crystal is also sheltered by the crevice and measures at least 0.1" (3 mm) in each dimension. All have a deep olive-green coloration with a hint of blue and a bright, adamantine luster, and are moderately translucent. There are many other Cuproadamite crystals scattered on the host rock, but these are nearly microscopic in size, and there is part of a vein of semicrystalline Cuproadamite that is easily visible.
no photo
cad-3 ($ 35.00)
Mina de Ojuela, Mapimi, Durango, Mexico
CUPROADAMITE specimen cad-4
$ 98.00
Dims: 2.4x2.1x0.8" (6.1x5.4x2.0 cm)
Wt: 1.80 oz. (51 g)
Tsumeb Mine, Tsumeb, Namibia
This small hand specimen consists almost entirely of intergrown cuproadamite crystals. On the top, many of them are exposed, revealing the diamond wedge shaped terminations of this mineral. These crystals are up to 4mm in length, and are a translucent green-turquoise in color, and not the purple often asociated with cuproadamite. Another unusual characteristic is that this specimen flouresces a deep purple under long-wave UV (not the bright green of adamite). The back of this specimen is covered with a thin druse of a very sparkly gray mineral which I have not identified.
no photo
cad-4 ($ 98.00)
Tsumeb Mine, Tsumeb, Namibia


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