THE MINERAL NICKELINE

  • Chemistry: NiAs, Nickel Arsenide.
  • Class: Sulfides
  • Subclass: Arsenides
  • Group: Nickeline
  • Uses: As a minor ore of nickel and as mineral specimens.
  • Specimens

Nickeline has somewhat of an identity crisis. It is alternatively known as niccolite (mostly in Europe). Reference books often use Nickeline (Niccolite) or Niccolite (Nickeline) as a heading. The growing trend and "official" name is nickeline as is used here.

Its first name was the German term "Kupfer nickel" or copper nickel. It sounds like some sort of alloy. It actually was a term of derision because nickel meant "nixes" or underground goblins. The miners in Germany who first saw the copper-red metallic mineral were convinced the mineral was a rich ore of copper. Instead, try as they might, no copper was to be produced from the nickel arsenide. The metal that was produced from the mineral was found to be useful and valuable and it is from this unflattering term that the metal received its name, nickel (Ni).

Nickeline is also the name of a group of hexagonal minerals of which the mineral nickeline is one of the more common members. Members of the Nickeline Group have a very simple formula, namely: AX. Where the metal ion, A, is either cobalt, palladium, platinum, nickel and/or iron and the X can be either arsenic, selenium, bismuth, tellurium and/or antimony with some members having some sulfur. All members of the group have nickeline's basic structure. They are all hexagonal and except for nickeline and pyrrhotite, are very uncommon to rare in occurrence.


These are the members of the Nickeline Group:

  • Breithauptite (Nickel Antimonide)
  • Freboldite (Cobalt Selenide)
  • Imgreite (Nickel Telluride)
  • Langistite (Cobalt Nickel Arsenide)
  • Nickeline (Nickel Arsenide)
  • Pyrrhotite (Iron Sulfide)
  • Sederholmite (Nickel Selenide)
  • Stumpflite (Platinum Antimonide Bismuthinide)
  • Sudburyite (Palladium Nickel Antimonide)

Niggliite (Platinum tin), was a member of this group and shares the same structure but is considered an alloy, having metallic bonds instead of ionic bonds.

Pyrrhotite has hexagonal and monoclinic components. The hexagonal components are placed in the Nickeline Group, but most natural pyrrhotite is a mixture of both components.


Nickeline's structure is fairly simple with the nickel ions, in hexagonal packing, forming stacked identical layers parallel to the major six-fold axis. The arsenic ions rest between the nickel ion layers, but in a staggered or alternating sequence such that the next layer is not in the same position as the previous layer. Each metal ion is surrounded by six arsenics; three below and three above. The major axis is actually a six-fold screw axis (helix) about the nickel ions.

A screw axis is an axis that has a rotation and a translation in the major axis direction. So, in this case, the axis will start with an arsenic ion at the base level. A rotation about the axis of 60 degrees and then movement (approximately 2.5 angstroms) along the axis produces the next arsenic ion. If this is done a total of six times, then the entire structure and consequently the symmetry of nickeline is reproduced. All members of the Nickeline Group share this basic structure, but with their own combination of elements of course.

Nickeline is not exactly a common mineral, but is found with other nickel and cobalt sulfide ores and thus it is included with them when mined for their various ores. This makes nickeline a minor ore of nickel and commercially important is some localities. The sulfides are usually hydrothermal in origin, although nickeline is also found in basic igneous rocks such as gabbros. Although crystals of nickeline are very scarce, some formations of nickeline can be attractive and an interesting addition to someone's collection.

PHYSICAL CHARACTERISTICS:

  • Color is copper-red to pink.
  • Luster is metallic.
  • Transparency: Crystals are opaque.
  • Crystal System: Hexagonal; 6/m 2/m 2/m
  • Crystal Habits are limited to mostly massive and granular components of massive hydrothermal sulfide rocks and gabbros, but a few localities have produced good pyramidal or tabular crystals. Columnar and reniform habits are also seen. Rare fourling twins are also seen.
  • Cleavage: Not observed.
  • Fracture: Uneven.
  • Hardness is 5 - 5.5
  • Specific Gravity is approximately 7.8 (well above average for metallic minerals)
  • Streak: Dark brown to black.
  • Other Characteristics: Will often develop a dark tarnish on fresh surfaces and weathered surfaces may have a coating of the green nickel arsenate, annabergite. Upon heating a garlic odor maybe observed due to the arsenic content. Crystals tend to be striated.
  • Associated Minerals include arsenopyrite, barite, silver, annabergite, cobaltite, pyrrhotite, pentlandite, chalcopyrite, breithauptite and maucherite.
  • Notable Occurrences include the Natsume nickel mine, Japan and at Mansfeld and Eisleben, Germany; Franklin, New Jersey; California and Colorado, USA; Styria, Austria; Sinaloa, Mexico; Talmessi, Anarak, Iran and at Great Slave Lake, Northwest Territories, Canada; Cobalt and Sudbury, Ontario, Canada as well as some sites in England, France, Morocco, Russia and southern Australia.
  • Best Field Indicators are color, density, associations, streak, hardness and odor when heated.
NICKELINE specimens:
(hover for more info)
NICKELINE specimen nic-1
$ 25.00
Dims: 3.7 x 2.3 x 1.3" (9.4 x 5.8 x 3.3 cm)
Wt: 6.11 oz. (173.2 g)
Nickel Mine, Cottonwood Canyon, near ghost town of Bolivia, Churchill County, Nevada, U.S.A.
This hand specimen consists of an amorphous chunk of Nickeline that is partly encrusted with a layer of what is likely annabergite. The Nickeline has a black coloration and a dull luster, and is essentially amorphous, so a damage assessment is not really applicable. However, close examination will show that the black color is caused by a decomposition coating that is only slightly worn in a few spots, where a tiny glimpse of the almost pinkish-gray coloration and metallic luster are peeking through. It is completely opaque, of course, and cracked and partly separated at one time. The cracks were subsequently filled in with the "annabergite". Besides these two minerals, there is no other material present.
no photo
nic-1 ($ 25.00)
Nickel Mine, Cottonwood Canyon, near ghost town of Bolivia, Churchill County, Nevada, U.S.A.
NICKELINE specimen nic-2
$ 25.00
Dims: 3.0 x 2.0 x 1.7" (7.6 x 5.1 x 4.3 cm)
Wt: 5.17 oz. (146.7 g)
Nickel Mine, Cottonwood Canyon, near ghost town of Bolivia, Churchill County, Nevada, U.S.A.
This piece consists of a chunk of amorphous Nickeline that is partly coated with a nickel mineral (likely annabergite). The Nickeline has a black color and a dull luster due to the presence of a decomposition coating, but close examination will reveal thin spots in the coating, where the almost pinkish-gray coloration and metallic luster of the mineral shines through. There is no actual host rock present, but the pale green "annabergite" is rather substantial, coating portions of the Nickeline in thick layers and extending in veins into the sulfide mineral.
no photo
nic-2 ($ 25.00)
Nickel Mine, Cottonwood Canyon, near ghost town of Bolivia, Churchill County, Nevada, U.S.A.
NICKELINE specimen nic-3
$ 30.00
Dims: 2.6 x 2.4 x 1.9" (6.6 x 6.1 x 4.8 cm)
Wt: 5.17 oz. (146.7 g)
Cu Pass Deposit, Great Slave Lake, Northwest Territories, Canada
This small but heavy hand specimen consists of a nearly pure chunk of Nickeline. It is amorphous, showing no crystal form, and is in reasonably good condition. Most of the piece is covered with a thin layer of a powdery, pale green substance which may be annabergite. However, there is a substantial portion that is rather freshly broken, revealing the Nickeline beneath. It has a bright metallic luster and a silvery-gray coloration with a very subtle hit of pink. There is no host rock on the specimen.
no photo
nic-3 ($ 30.00)
Cu Pass Deposit, Great Slave Lake, Northwest Territories, Canada
NICKELINE specimen nic-4
$ 30.00
Dims: 3.0 x 2.6 x 2.0" (7.6 x 6.6 x 5.1 cm)
Wt: 1 lb., 2.2 oz. (516 g)
Cu Pass Deposit, Great Slave Lake, Northwest Territories, Canada
Most of the surface of this hand-sized Nickeline specimen is covered with a thin coating of a chalky, dull, pale-green material that may be annabergite. There is one rough face, however, that is the result of breakage and shows the metallic luster and pinkish, almost pale copper color of the amorphous, massive Nickeline. There are a few spots on this face which have a very dull luster; this may be evidence of a crevice in the material where it was later broken, or the material may have been broken once before, left to oxidize, and then broken again, though less severely so. There is no host rock present.
no photo
nic-4 ($ 30.00)
Cu Pass Deposit, Great Slave Lake, Northwest Territories, Canada
NICKELINE specimen nic-5
$ 30.00
Dims: 2.8 x 2.6 x 1.6" (7.1 x 6.6 x 4.1 cm)
Wt: 1 lb., 2.8 oz. (534 g)
Cu Pass Deposit, Great Slave Lake, Northwest Territories, Canada
This amorphous chunk of Nickeline is different from our other specimens in the fact that a substantial amount of host rock is attached to it. The host rock appears to be made up of a feldspar that is intersected by a few thin calcite or limestone veins. This host material has a pale gray coloration and a pearly luster, and is attached to the Nickeline along a very flat plane. The Nickeline itself has the standard high density, metallic luster, and pale, almost coppery pink-gray coloration. Some of its surfaces are covered with a thin layer of a pale green, powdery substance.
no photo
nic-5 ($ 30.00)
Cu Pass Deposit, Great Slave Lake, Northwest Territories, Canada
NICKELINE specimen nic-6
$ 80.00
Dims: 3.1 x 2.9 x 1.0" (7.9 x 7.4 x 2.5 cm)
Wt: 1 lb., 2.3 oz. (519 g)
Cu Pass Deposit, Great Slave Lake, Northwest Territories, Canada
This hand specimen consists of a chunk of nearly pure Nickeline that has a cut and polished face. The face and small amount of unpolished breakage surface show the pale, coppery-red coloration and metallic luster that are standard for Nickeline, and many tiny hairline cracks are visible through the polished face. Those rough faces that are not freshly broken are coated with a thin layer of a powdery, pale-green substance that is obviously a nickel mineral. There is also a small amount of what is likely a feldspar on one end of the piece.
no photo
nic-6 ($ 80.00)
Cu Pass Deposit, Great Slave Lake, Northwest Territories, Canada
NICKELINE specimen nic-7
$ 42.00
Dims: 2.1 x 1.0 x 0.5" (5.2 x 2.5 x 1.3 cm)
Ait Hamane, Maroc
(2 pc.) This specimen consists of two chunks of massive Nickeline. Both are broken off of another piece, and thus show fresh breakage on most of their surfaces. Any original surfaces that are present show weathering and are mostly coated with a thin layer of annabergite dust. Their fresh surfaces show the classic pale coppery-red color and metallic luster.
no photo
nic-7 ($ 42.00)
Ait Hamane, Maroc
NICKELINE specimen nic-8
$ 30.00
Dims:1.0x0.7x0.5" (2.5x1.8x1.3 cm)
Wt: 0.7oz. (20g)w/box
Baita Biher, Romania
This specimen consists of a mass of golden-bronze nickeline on a piece of matrix. Upon examination with a loupe, it appears that this specimen may at least semi-crystalline. There is no damage to this specimen. It is secured within a plastic "perky" box.
no photo
nic-8 ($ 30.00)
Baita Biher, Romania
NICKELINE specimen nic-9
$ 60.00
Dims: 2.5x1.6x1.6" (6.4x4.1x4.0cm)
Wt: 5.88oz. (166.3g)
Wechselschacht, Richelsdorf, Hessen, Germany
This specimen is mostly nickeline, with crystals of the unidentified host mineral embedded in places. The nickeline has a distinctive and unusual color, not red enough to be copper, yet too red to be nickel. The specimen also has an appealing luster, espeically upon the brigher "fresh" faces, while the other side is somewhat dull.
no photo
nic-9 ($ 60.00)
Wechselschacht, Richelsdorf, Hessen, Germany
NICKELINE specimen nic-10
$ 70.00
Dims: 1.22x1.06x0.59" (3.1x2.7x1.5cm)
Wt: 0.88oz. (24.9g)
Germany
This specimen appears to be mostly nickeline. The color is a metallic red, a little more red than copper. It has a bit of a darker tarnish, irridescent under a loupe. The crystals on top of the specimen mostly have a rounded, almost botryoidal appearance, although there are a few small prismatic crystals. There is another mineral present, it is silvery white, metallic, and looks cleaved or striated in different places. I suspect that it is either silver or gersdorfite, although I am not certain of either.
no photo
nic-10 ($ 70.00)
Germany
NICKELINE specimen nic-11
$ 25.00
Dims: 1.05x0.85x0.60" (2.66x2.17x1.53cm)
Wt: 1.04oz (29.4g)
Jachymov, Czech Republic
This specimen contains several distinct minerals, most notably pinkish metallic crystals of nickeline. These do not show good crystal form, as they are intergrown with another metalic mineral that is silvery-white in color, probably arsenopyrite. Also, there are several veins of a translucent white mineral, which does not show good crystals, although there are a few angles that look hexagonal (so it looks more like quartz than calcite).
no photo
nic-11 ($ 25.00)
Jachymov, Czech Republic

 


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