Euxenite Gemstone: Properties, Meanings, Value & More

Euxenite (pronounced YOOK-suh-neyet) is a heavy, complex mineral containing many rare earth elements. Scientifically, it’s called euxenite-(Y), the (Y) being for yttrium.

Some call euxenite a “trash can mineral” because it can have so many elements in its structure, similarly to hornblende or tourmaline.

Is euxenite rare? As a mineral, not so much. But faceted euxenite gemstones are quite rare, usually only cut for collectors.

Industrially, euxenite is valuable in many fields.

Today, we’ll cover all of euxenite’s uses, properties, prices, history, and more!

Pictured above: Rare-earth mineral euxenite from Madagascar; Musée des Confluences. Lyon | Image credit: Ismoon, GNU Free Documentation License

About Euxenite Stone

Euxenite is a rare semi-precious gemstone usually found in dark colors like brown to black. The proper scientific name is euxenite-(Y).

Polycrase-(Y) is a mineral very similar to euxenite — so similar, in fact, that some mineralogists consider them identical. The International Mineralogical Association (IMA) has not approved polycrase-(Y) as an official mineral species.

Euxenite Uses

Euxenite is a minor ore of rare earth elements, particularly niobium and tantalum.

The only minerals used as tantalum ores industrially are tantalite, microlite, wodginite, polycrase, and euxenite.

Tantalum is primarily used in:

• Medical tools & materials like surgical threads, radioactive tracers, and contrast agents for CTs & MRIs

• Surgical implants like artificial joints, nerve repair nets, cranial plates, hemostasis materials & heart or vascular stents

• Strong, flexible, high-temperature alloys for applications like metal-cutting carbides, jet engines & nuclear reactors

• Electrical components like resistors & capacitors for products like computers, cameras & cell phones

• Vessels for chemical reactions with corrosive fluids

• Radiation shielding (e.g. on Voyager 1 and Voyager 2 spacecraft)

• High refractive index glass in camera lenses

The primary uses for niobium are for:

• Stronger, more weldable iron and steel with higher resistance to temperature, oxidation, & corrosion

• Superconductors for storing energy in magnetic fields (SMES systems), generators, nuclear MRI equipment, & nuclear magnetic resonance spectrometers

• Aerospace parts like engines & gas turbine blades

• Atomic energy reactors & nuclear fuel alloys

• Electronic, laser tech, and infrared components like capacitors, tubes & vacuum devices

• Medical / surgical tools & implants like bone screws or plates, artificial tooth roots & surgical instruments

• Acid- and metal-resistant chemical equipment & catalysts

• Metallurgy tools like metal-cutting carbides & graphite sheets used in car parts

Pictured above: Euxenite (Weight: 16.67 g) – Place of discovery: Harare, Zimbabwe (formerly Salisbury, Rhodesia) | Image credit: © Raimond Spekking / CC BY-SA 4.0 (via Wikimedia Commons)

Euxenite Specifications & Characteristics

The mineral euxenite-(Y) always contains yttrium, niobium, and titanium. Calcium, cerium, uranium, thorium, and tantalum are often present.

A fairly complex mineral, euxenite’s chemical formula is often written as (Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6. Typically, the niobium and tantalum content (together) are close to or equal to the titanium content.

The euxenite formula approved by the IMA is simply Y(NbTi)O6, but they also list the mineral tanteuxenite-(Y) with the formula Y(TaTi)O6. Euxenite-(Y) is isostructural with tanteuxenite-(Y).

Euxenite is in the eponymous euxenite group, along with:

• Fersemite

• Kobeite-(Y)

• Loranskite-(Y)

• Tanteuxenite-(Y)

• Uranopolycrase

• Yttrocrasite-(Y)

The mineral forms a series with polycrase-(Y). It forms another series with columbite, specifically columbite-(Fe) and columbite-(Mn).

In terms of crystal habits, euxenite is often metamict, meaning it’s become non-crystalline or partially amorphous due to gradual radioactive decay. Heating metamict euxenite can restore its crystalline structure.

Non-metamict euxenite is found as stout and prismatic crystals with parallel striations.

Euxenite also occurs as compact masses, grains with partial to no crystal faces, or crystal aggregates that can be radiating, parallel, or subparallel.

Twinning is common on {201} and rare on {013} or {101}.

Euxenite properties listed:

• Mohs hardness: 5.5-6.5

• Color: Black, brownish-black, greenish-black, olive-green; Yellowish-brown or brown in transmitted light

• Crystal structure: Orthorhombic; May be partially or fully amorphous if metamict

• Luster: Submetallic, greasy, vitreous, or resinous; Waxy or resinous on fracture surfaces

• Transparency: Translucent to opaque; Very rarely transparent in fragments

• Refractive index: 2.06-2.24

• Density: 4.30-5.90; Varies by tantalum content

• Cleavage: None

• Fracture: Conchoidal or sub-conchoidal

• Streak: Grayish-brown, yellowish-brown, or reddish-brown

• Luminescence: None

• Pleochroism: None

• Birefringence: None

• Dispersion: None

Pictured above: White and pink euxenite museum specimen from Wakefield Township in Quebec, Canada | Image credit: Pacific Museum of Earth from Canada, CC-BY-SA-2.0

Euxenite History

The first description of euxenite, published in 1840, was based on specimens from Vestland, Norway. German-Norwegian mineralogist Theodor Scheerer wrote the description.

Scheerer chose the name “euxenite” from the Greek euxenos, meaning “hospitable” or “friendly to strangers” because the mineral contains so many rare, important elements.

Other monikers used for euxenite in the past:

• Guimaraesite

• Lyndochite

• Polycrase-(Y)

“Guimaraesite” was described by Brazilian geochemist Djalma Guimarães in 1926 as a titanium, uranium, iron columbate and tantalate. Gagarin & Cuomo chose this name in 1951, but it was later found to be euxenite-(Y).

As of 2006, “guimarãesite” is used for a complex calcium zinc magnesium beryllium phosphate mineral.

Canadian geologist Hardy Vincent Ellsworth used “lyndochite” first in 1927 for specimens from Lyndoch Township in Ontario, Canada. Originally thought to be a new columbite group mineral, later analysis revealed it as a minor euxenite-(Y) variety.

In 1928, Australian mineralogist and geochemist Edward Sydney Simpson first described the mineral tanteuxenite, later adjusted to tanteuxenite-(Y), from Western Australia.

Pictured above: Euxenite, crystals aggregation (11 cm) - Vegusdal, Norway | Image credit: Aangelo, GNU Free Documentation License

Euxenite Healing Properties

A predominantly black healing stone, euxenite’s meaning reflects the grounding and protective properties of other black gemstones. It’s also a powerful root chakra stone.

Heads up: if you use euxenite for crystal healing, don’t use it in any crystal elixirs or consume it.

Physical Healing

Physically, euxenite is believed to treat issues related to:

• Immune system function

• Fatigue

• Muscle weakness

• Endurance

• Nutrient absorption

Outside of metaphysical healing, euxenite’s rare earth elements are also used in various medical applications.

Emotional Healing

Emotionally, euxenite crystals are said to be nourishing, protecting you from stress and helping you work through difficult feelings. Their grounding properties may also help you be more mindful, resilient, and conscientious.

Euxenite Gemstone Properties

Due to its rarity in gemstone form, there aren’t standard euxenite grading criteria. We’ll still touch on how the standard grading factors may apply to euxenite’s value:

• Color: Almost all euxenite stones are dark in tone, often gray or black, so any prominent colors or undertones like green or yellow can add value. Many faceted euxenite gems are opaque and black with light brown splotches or veining.

• Cut: Euxenite is rarely faceted, making faceted options rarer and somewhat more valuable. Occasionally, euxenite is cut into cabochons. Most gems are cut specifically for collectors. Most euxenites for sale are rough (uncut).

• Transparency: Most euxenites are opaque or sometimes translucent on thin edges. Rarely, euxenite crystals have transparent fragments.

• Carat Weight & Size: The rare transparent euxenite fragments can be cut into faceted gems, but these are always tiny. Even translucent to opaque euxenite gems are pretty much always small. You can find opaque faceted euxenite gems up to 4 carats.

Before it’s cut or sold, how does euxenite form?

Pictured above: Euxenite-(Y) specimen from Colorado with typical greasy luster and black color for locality; Good reference specimen from the Richard A. Kosnar collection | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Euxenite Formation & Sources

Euxenite minerals form in a magmatic sequence (as magma cools into a rock) when titanium activity increases while tantalum, niobium, manganese, and iron activity decreases.

The sequence starts with columbite-(Fe), then titanium-bearing ixiolite and ferrowodginite, then samarskite group minerals, then euxenite group minerals.

If the rock containing euxenite minerals is altered by hydrothermal fluids via metasomatism, the minerals can alter into various pyrochlore minerals.

Euxenite is found in granite pegmatites and placer or detrital black sand deposits.

Where is euxenite found geographically?

Mining Locations

The main sources of attractive euxenite crystals are Norway and Canada. Large crystals are also found in Wyoming, USA.

Additional notable euxenite sources include:

• Australia

• Brazil

• Finland

• Greenland

• Madagascar

• Russia

• Sweden

• USA (Arizona, California, Colorado, Maine, Pennsylvania, Virginia)

• Zaire

Pictured above: Red crystalline euxenite-(Y) specimen from Texas, USA; Collected by Frank Roberts, 2007; Trade from Art Smith; K. Nash specimen & photo | Image credit: Kelly Nash, CC-BY-SA-3.0

Euxenite Price & Value

Faceted euxenite gemstone prices aren’t necessarily low, but they’re lower than you’d expect considering their rarity — probably because it’s in low-demand.

Overall, faceted euxenites cost around $11 to $40 per carat or roughly $40 to $100 each.

Rough (uncut) euxenite prices range from about $15 to $160 each. Mostly pale brown crystals tend to be less valuable unless they’re larger. Shiny black or deep blue crystals usually have higher prices.

Euxenite Care and Maintenance

First, is euxenite radioactive? It may be, as the common impurities uranium and thorium are radioactive. The rare earth elements in euxenite also present a risk for toxicity.

Contact with rare earth elements on the skin, eyes, or respiratory system (inhaling rare earth dusts) can cause irritation, injury, and diseases like bronchitis or pneumonitis if you’re exposed to large amounts.

Those at the biggest risk are lapidarists (gem cutters), who should take abundant safety precautions. If you’re not cutting euxenite, you should handle the gem carefully, ideally keeping it in an enclosed display case that pets or children can’t access.

Since radioactivity is a risk, we recommend keeping a Geiger counter to make sure it’s not emitting any dangerous levels of radiation into the room.

Find more information in our article on safety tips for handling toxic and radioactive gems.

Elevate Your Collection with Euxenite!

Euxenite may seem a bit scary, but with proper handling, this gorgeous gemstone is an enviable stone to have. From lustrous black crystals to deep blue specimens, and plenty of unique traits added in, euxenite is a stunner indeed — far beyond its “garbage can” nickname.

Buy euxenite and other exquisite gemstones today!