• Chemistry: Cu3V2O7(OH)2 - 2H2O, Hydrated Copper Vanadate Hydroxide.
  • Class: Phosphates
  • Subclass: Vanadates
  • Uses: Only as mineral specimens.
  • Specimens

Volborthite is a rare copper vanadate mineral that was named for a Russian paleontologist; Aleksandr Fedorovich van Volborth. It was first named knaufite which is still considered a synonym. Volborthite can form encrusting masses with a beautiful yellow green coloration and pearly luster.

Volborthite is not all that closely related to the mineral calciovolborthite except that both are vanadate hydroxides. Obviously, volborthite lacks the calcium, but also has water molecules in its structure. Volborthite's formula could be written as Cu3(VO4)2 - 3H2O. But this formula does not show the true cationic unit as a pyrovanadate group; V2O7. The basic structure of volborthite is a sheet-like structure with copper oxide/hydroxide layers that are held together by the pyrovanadate groups and then these layers are stacked by layers of water.


  • Color is yellow to green-yellow or light brown.
  • Luster is vitreous, pearly or dull.
  • Transparency: Specimens are translucent to opaque.
  • Crystal System is monoclinic; 2/m
  • Crystal Habit is typically encrusting or rounded masses, also individual scales. Lamellar twinning is sometimes seem.
  • Cleavage is imperfect.
  • Hardness is 3.5
  • Specific Gravity is approximately 3.4 - 3.5 (heavy for non-metallic minerals)
  • Streak is pale green.
  • Other Characteristics: Non-fluorescent.
  • Notable Occurrences include the type localities of Sisersk and Nizhne Tagilsk, Ural Mts, Russia as well as numerous localities in Arizona; Carlin Gold Mine, Nevada USA; Mt. Vesuvius, Italy; Wheal Edward, Cornwall, England; Tugao, Inuyama, Aichi, Japan; Paull's Consolidated Mine, South Australia, Australia; Pribram, Czech Republic; Copiapo, Chile; Salzburg, Austria and Vancouver Island, Canada.
  • Best Field Indicators are color, locality, non-fluorescence and density.
VOLBORTHITE specimens:
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VOLBORTHITE specimen vol-1
$ 72.00
Dims: 2.64x1.66x0.67" (6.71x4.21x1.69cm)
Wt: 1.22oz (34.6g)
Monument Valley, Navajo County, Arizona, USA
This large sliver of rock is essentially covered with volborthite, most of which is a non-crystalline crust in several shades of pale green. Some areas have a fine moss-like appearance, almost velvety under a loupe. The thicker (and more protected areas) appear sparkly and a deeper green, and my loupe reveals that the volborthite in these areas is organized in tiny green rosettes, looking very much like the larger rosettes that barite often forms. This is a very pretty specimen of this rare mineral.
no photo
vol-1 ($ 72.00)
Monument Valley, Navajo County, Arizona, USA
VOLBORTHITE specimen vol-2
$ 55.00
Dims: 2.70x1.69x0.94" (6.86x4.30x2.40cm)
Wt: 2.77oz (78.3g)
Monument #1 Mine, Navajo County, Arizona, USA
This rock is host to two distinct minerals. The yellow mineral on one face is volborthite in fuzzy yellow masses or tiny intergrown blades (remeniscent of barite rosettes). The flat blades have a pearly luster, and a slightly green tint to their yellow color. The other mineral is distinctly green, more massive in appearance (with little indication of crystals), and occurs in patches on all sides of the specimen. I believe this mineral is calciovolborthite, although it is difficult to be certain when crystals are not visible.
no photo
vol-2 ($ 55.00)
Monument #1 Mine, Navajo County, Arizona, USA


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