Niccolite (Nickeline) Gem: Properties, Meaning, Uses & Value

Niccolite, or nickeline, is a shimmering, metallic mineral with gorgeous peachy-red to copper-red coloring. It’s mostly known among collectors, but historians may know it as the catalyst for the first isolation of nickel.

Is niccolite a gemstone? Yep! Niccolite is the only stone in the eponymous nickeline mineral group to commonly be used in jewelry.

The mineral niccolite is fairly common, but gemstones are somewhat rare. Though not usually faceted, as crystals are scarce, massive niccolite is cut into cabochons and carvings for accessories like rings, pendants, and even bolo ties.

Ready to know more? Today, we’re sharing the insights we’ve learned through decades of experience in the gem industry to teach you all about niccolite, from its properties and uses to its history and prices.

Pictured above: Niccolite crystal from Germany | Image credit: Christian Rewitzer

About Niccolite Stone

Niccolite is a reddish semi-precious gemstone with many monikers, most notably “nickeline.” Some of the mineral’s other nicknames aren’t accurate (noted with * below):

• Nickelite

• Rotnickelkies

• Arsenical Nickel / Arsennickel / Arseniknickel

• Copper Nickel*

• Kupfernickel* / Kupfernicker* / Kupfernikkel* (all meaning copper-nickel)

We’ll discuss the niccolite vs nickeline debate in the History section later. For now, we’ll note that both are still used. Also, “nickelite” is used for a different tin-based babbitt metal (aka “bearing metal”) alloy.

Industrially, what is nickeline used for?

Niccolite Uses

Niccolite has been used as a nickel ore, but it’s not the first choice because its arsenic content has damaging effects during milling (separating valuable minerals from waste rock) and smelting (extracting the metal from the mineral).

To combat this, metallurgists can treat nickeline by combining it with ore minerals that don’t contain arsenic. However, niccolite’s heaviness makes this treatment difficult because it involves flotation.

Plus, stripping the arsenic during smelting still requires a lot more steps and additives (e.g. fluxes, reagents) to get arsenic-free nickel.

More often, minerals like limonite or pentlandite are used to source nickel.

Additionally, niccolite has been created synthetically to research its geological properties.

Speaking of those properties, what is the formula for niccolite?

Niccolite Specifications & Characteristics

As a nickel arsenide, niccolite’s formula is NiAs. The make-up is typically about 56 percent arsenic and 44 percent nickel, but impurities can change these. Common impurities are antimony, iron, cobalt, and sulfur.

Antimony can be present in larger amounts, partially replacing arsenic. These antimony niccolite specimens are isomorphous with breithauptite.

Breithauptite is also in the nickeline group with niccolite. Other members include:

• Achavalite

• Freboldite

• Kotulskite

• Langistite

• Sederholmite

• Sobolevskite

• Strumpflite

• Sudburyite

• Vavřínite

• Zlatogorite

In terms of habits, niccolite crystals may be distorted, terminated, and horizontally striated. Niccolite crystals are rare, though.

More often, the mineral occurs as granular aggregates, columnar to reniform (kidney-shaped) masses, or growths that are reticulated (network-like) and arborescent (tree-like).

Twinning can occur on {1011}, resulting in four-crystal compounds called fourlings. Sometimes twinning happens on {3141}.

Niccolite properties listed:

• Mohs hardness: 5-5.5

• Color: Pale copper red, peachy-red; Very strong anisotropism in pale greenish-yellow to slate-gray; Tarnishes to gray, grayish-black, or black

• Crystal structure: Hexagonal

• Luster: Metallic

• Transparency: Opaque

• Refractive index: Complex due to anisotropism

• Density: 7.78-7.80

• Cleavage: None

• Fracture: Conchoidal or irregular/uneven

• Streak: Pale brownish-black

• Luminescence: None

• Pleochroism: Present & strong in reflected light - whitish yellow-pink to pale brownish-pink

• Birefringence: None

• Dispersion: Weak to strong; r > v

Pictured above: Showy, rich ore specimen of lustrous rose gold niccolite with micro-crystals of cobaltite and micro wires of silver; Richard Hauck Collection | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Niccolite History

Niccolite has gone through many name changes over time.

Swedish chemist & geologist Urban Hjärne published the first name for this mineral in 1694: kupfernickel in German or kopparnickel in Swedish.

The terms derived from the nickname “Nickel” for a German trickster sprite also called Satan or Old Nick, and kupfer or koppar meaning “copper” — thus, “The Devil’s Copper.”

The names originally came from 1650s copper miners in the German Ore Mountains finding niccolite, thinking it was copper ore, then not obtaining any copper from it and getting sick (mysteriously to them, but probably from arsenic poisoning).

In 1751, Swedish mineralogist & chemist Baron Axel Fredrik Cronstedt became the first person to successfully isolate nickel by trying to extract copper from a “kupfernickel” stone. He named the white metal he ended up extracting “nickel.”

In 1832, French mineralogist & geologist François Sulpice Beudant renamed the mineral “nickeline” for its nickel content.

Similarly, American scientist James Dwight Dana proposed the name “niccolite” in 1868 from the Latin niccolum, meaning “nickel.”

The International Mineralogical Association (IMA) recommended the name nickeline over niccolite or nickelite in 1971.

Niccolite Healing Properties

As a red healing stone, niccolite can provide the strengthening and motivating properties of other red gemstones. It’s also used as a root or solar plexus chakra stone.

Physical Healing

Physically, crystal healers recommend niccolite for treating issues related to:

• Stomach

• Digestion

• Liver

• Bones

• Leg or foot pain

Emotional Healing

Emotionally, niccolite is believed to:

• Encourage personal growth

• Increase mental clarity

• Facilitate creative expression

• Promote resilience

• Raise intuition

• Enable relationship stability

Pictured above: Rough, metallic niccolite specimen from Germany | Image credit: Leon Hupperichs

Niccolite Gemstone Properties

Besides rarity, niccolite’s value also depends on color, cut, and carat weight.

Color

The best niccolite colors are subjective, but most can agree that non-tarnished niccolite is better, with coppery to peachy red hues.

Cut

Niccolite is rarely faceted, since crystals are rare. The rare faceted niccolite gems cut often have trillion shapes.

More often, niccolite is cut into cabochons or carvings. It’s also commonly sold rough (uncut) or polished, highlighting its metallic luster.

Carat Weight & Size

Massive niccolite can be quite large, yielding cabochons or carvings of virtually any size. Though more limited, faceted niccolite gems have been cut up to 20 carats.

Treatments

Niccolite doesn’t receive traditional gem treatments, but many people apply a surface coating of nail polish to prevent the stone from tarnishing.

Now, how is niccolite formed?

Pictured above: Red proustite crystals on dark gray, massive nickel matrix across calcite | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Niccolite Formation & Sources

Niccolite minerals form when ultramafic rocks and ore deposits undergo hydrothermal alteration.

The formation may happen when nickel-copper sulfides are replaced by niccolite or metasomatic fluids containing sulfur, carbonate, and arsenic alter previously sulfide-free ultramafic rocks.

Humidity can cause nickel to transform into annabergite.

Miners may find niccolite in hydrothermal vein deposits, peridotites, or norites.

Mining Locations

The best sources for niccolite gem material are in Ontario, Canada.

Other gem-quality niccolite sources:

• Austria

• Canada

• Czech Republic

• France

• Germany

• Japan

• Mexico

• Morocco

• Slovakia

• USA (California, Colorado, New Jersey)

Pictured above: Wedge-shaped combination of bronzy massive niccolite in botryoidal to massive bismuth matrix; From old historic locale in Germany | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Niccolite Price & Value

Faceted niccolites cost about $10-$90 per carat or $70-$660 total.

Niccolite cabochons are more accessible, priced around $1-$3 per carat or $35-$50 total. Polished or tumbled niccolites are similar at $25-$60 each.

Rough niccolite specimens vary broadly in price, starting at $20 and reaching $4,500. Most fall between $20 to $120.

The most common niccolite jewelry type is a pendant, priced from $70-$170 or up to $630 with other gems incorporated.

Niccolite Care and Maintenance

Proper safety is crucial for niccolite.

The nickel and arsenic content is toxic, so follow our safety tips here. Most importantly, wear eye protection, don’t ingest or inhale any particles, and wash your hands after handling.

For gemstone care, store niccolite in a secure, dry place to prevent tarnishing or pets/children accessing it.

Only wear niccolite jewelry occasionally and opt for protective settings.

Keep the stone away from other gemstones to avoid scratches.

Niccolite: A Niche Stone of Many Names!

No matter what you call it, niccolite (or nickeline) is a fascinating stone with shimmering metallic luster and gorgeous red hues. Combined with its centuries of history and rarity in gem form, niccolite is a treat for any collector or rare gem enthusiast.

Buy niccolite and other niche gemstones today!