Samarskite Gemstone: Properties, Meanings, Value & More

Samarskite is a unique rare-earth mineral or mineral series of mostly black or brown stones. The main member of the samarskite group, often simply called “samarskite” is the yttrium-bearing variety samarskite-(Y).

The mineral is quite heavy, with an even higher density than pyrite.

While samarskite minerals are somewhat common, they’re quite rare as gemstones. This is largely considered a collector’s stone.

Want to know more? We’ve got you covered! Today, learn all about samarskite’s properties, uses, prices, history, and more!

Pictured above: Cluster of samarskite-(Y) crystals from Tom Ross Mine in Yancey Co, North Carolina; Richard Hauck Collection | Image credit: Kelly Nash, CC-BY-SA-3.0

About Samarskite Stone

Samarskite is a rare semi-precious gemstone mostly known among collectors of unusual gemstones.

The stone has had many monikers, like:

• Adelfolite / Adelpholite

• Ampangabéite

• Ånnerödite

• Eytlandite

• Hydroeuxenite

• Hydrosamarskite

• Nuevite

• Uranoniobite

• Uranotantal / Uranotantalite

• Yttroilmenite

But samarskite is best known for its uses outside the gemstone world.

Samarskite Uses

Samarskite is an ore mineral of samarium, an important rare-earth element also found in monazite and bastnasite. Samarium is an impurity in all three minerals.

Significant uses for samarium are:

• Samarium-cobalt permanent magnets — High resistance to corrosion and demagnetization; Often used in motors, speakers, headphones, MRIs, generators

• Nuclear reactor control rods — High neutron absorption

• Organic synthesis of drugs — Reducing & coupling agent; Used to create Taxol, a cancer-treating drug, and Quadramet, a pain treatment for bone cancer

• Geochronometer — Determines age and origin of rocks

• Catalyst for chemical reactions — Used in electrochemical dinitrogen reduction reaction (NRR), a sustainable energy alternative for carbon neutrality, and removing water & hydrogen from ethanol

Other minor uses of samarium are in:

• Carbon arc lights (used in film & TV)

• Lighter flint

• Optical & infrared absorbing glass

Samarskite-(Yb) is notable for being one of the few mineral sources of ytterbium, alongside others like monazite, euxenite, and xenotime.

A notable study with samarskite was conducted in 1992, when NASA experimented on growing samarskite crystals under conditions by the traveling solvent float zone (TSFZ) method, pictured below.

Pictured above: Paylod Commander (PLC) Mark Lee conducts experiment M20 (Growth of Samarskite Crystal in Microgravity) in Spacelab-Japan | Image credit: National Archives at College Park - Still Pictures, Public domain

Samarskite Specifications & Characteristics

Samarskite is technically a series of minerals, the main two being samarskite-(Y) and samarskite-(Yb), the only ones with “samarskite” names.

What is the chemical composition of samarskite?

1. Samarskite-(Y) contains yttrium, ferric iron, niobium, and oxygen. The samarskite-(Y) formula is YFe3+Nb2O8.

2. Samarskite-(Yb) contains ytterbium, ferric iron, oxygen, and niobium, plus sometimes tantalum. The samarskite-(Yb) formula is YbFe3+(Nb,Ta)2O8 or YbNbO4.

Common impurities in samarskite-(Yb) include uranium, thorium, calcium, ferrous iron, tantalum, erbium, yttrium, and dysprosium. Samarium, uranium, titanium dioxide, and cerium are common impurities in samarskite-(Y).

The formula for the samarskite group (part of the columbite supergroup) is A3+B3+C5+2O8, where:

• A can be ytterbium, yttrium, lanthanide, uranium, thorium, or calcium

• B can be ferric iron or manganese (Mn2+)

• C can be niobium, tantalum, or titanium, but niobium must exceed tantalum and titanium

Samarskite-(Y) crystals are prismatic & stubby, tabular, or elongated with pyramidal ends. More often, the mineral is granular, compact, and/or massive.

Many samarskite-(Yb) crystals are metamict, meaning they’ve lost their crystal structure from radioactive decay, usually from high uranium impurities.

Samarskite Properties

These are the properties for samarskite-(Y) and samarskite-(Yb), with differentiations noted when applicable:

• Mohs hardness: 5-6

• Color: (Y) - Black, brownish-black; Often brown or yellowish-brown surface; (Yb) - Black; Metamict material - Brown to yellowish-brown

• Crystal structure: Monoclinic or orthorhombic

• Luster: (Y) - Vitreous, resinous, or sub-metallic; Yb - Vitreous; Metamict material - Dull

• Transparency: Opaque; Sometimes transparent in thin fragments

• Refractive index: (Y) - 2.10-2.20; (Yb) - Over 2.10

• Density: (Y) - 5.25-5.69; (Yb) - 7.03

• Cleavage: (Y) - Indistinct/Poor on {010}; (Yb) - None

• Fracture: Conchoidal

• Streak: (Y) - Dark reddish-brown, yellowish-brown, or black; (Yb) - Brown to black; Metamict material - Gray

• Luminescence: None

• Pleochroism: None

• Birefringence: None (due to metamictization)

• Dispersion: None

Pictured above: Yttrotantalite specimen with brick-red pyrite crystals in small vug; From type locality (Ytterby pegmatite in Sweden); Mullane Collection | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Types of Samarskite

Below is the complete list of minerals in the samarskite group:

• Calciosamarskite: Orthorhombic; Formula (Ca,U4+)Fe3+(Nb,Ta,Ti)2O8 or (Ca,Fe,Y)(Nb,Ta,Ti)O4 by IMA

• Ishikawaite: Monoclinic; Formula U4+Fe2+Nb2O8 or (U,Fe,Y)NbO4 by IMA

• Samarskite-(Y): Monoclinic; Formula YFe3+Nb2O8

• Samarskite-(Yb): Monoclinic; Formula YbFe3+(Nb,Ta)2O8

• Shakhdaraite-(Y): Monoclinic; Formula ScYNb2O8

• Srilankite: Orthorhombic; Formula ZrTi2O6 or TiO2 by IMA

• Yttrotantalite-(Y): Orthorhombic; Formula (Y,U,Fe2+)(Ta,Nb)(O,OH)4

But who discovered samarskite first?

Samarskite History

Samarskite was first discovered by German mineralogist Gustav Rose and German geographer & polymath Alexander von Humboldt. They found the mineral around 1832 in the Ilmen Mountains of Russia (Siberia).

Gustav Rose wrote the first description of samarskite in 1839 but called it “uranotantalite” for its uranium and tantalum content.

In 1847, his brother Heinrich Rose published an updated analysis that revealed a predominant niobium content, calling it “uranoniobite.”

However, Heinrich Rose proposed another name in his 1847 description: samarskite. The origin of this name? Honoring Russian mining engineer (and Chief of Staff of the Russian Corps of Mining Engineers) Colonel Vasily Samarsky-Bykhovets, who gave Rose high-quality specimens to study.

In 1881, Norwegian geologist Waldemar Christofer Brøgger (or Brögger) and Swedish chemist Christian Wilhelm Blomstrand published a description of a mineral they called “ånnerödite.”

They described it as “essentially a pyro-niobate of uranium and yttrium” but the formula was nearly identical to samarskite.

But why is samarium named samarium?

Pictured above: François Lecoq de Boisbaudran, discoverer of gallium, samarium, and dysprosium | Image credit: Orange.fr, Public domain

History of Samarium

Swiss chemist Jean Charles Galissard de Marignac first observed samarium in 1853 using spectroscopy on a material called “dydimia.”

In the late 1870s, more samarskite was found in North America. Consequently, scientists favored samarskite for isolating rare-earth elements.

In 1879, French chemist Paul-Émile (François) Lecoq de Boisbaudran (pictured above) became the first to isolate and name samarium from samarskite.

French chemist Eugène-Anatole Demarçay first isolated the element “radical Σ” (now called europium) in 1901. This came after his finding in 1896 that de Boisbaudran’s samarium oxide sample was contaminated by the element.

Discovery of Other Samarskite Minerals

Here’s the list of the subsequent samarskite minerals discovered:

1. Yttrotantalite-(Y): First described from Ytterby, Sweden, as “yttrotantalite” in 1802 then “yttroilmenite” by German chemist Rudolf Hermann in 1846; Relationship to samarskite identified by Gustav Rose in 1847; Renamed by IMA in 2022

2. Ishikawaite: First described from Ishikawa District, Japan, in 1922 by Yuji Shibata and Kenjiro Kimura as a uranium-rich, REE-poor mineral with the formula YNbO4; Redefined in 1999 with the formula (U,Fe)NbO4

3. Calciosamarskite: First described from Ontario, Canada, in 1928 by Hardy Vincent Ellsworth of Canadian Geological Survey as calcium-rich samarskite variety

4. Srilankite: First described from Rakwana, Sri Lanka, in 1983 by Alexander Willgallis, Eveline Siegmann, and Theja Hettiaratchi

5. Samarskite-(Yb): First described from Colorado, USA, in 2004 by Sarah L. Hanson et al.

6. Shakhdaraite-(Y): First proposed to IMA in 2020 & described in 2022 by Pautov et al. for specimens from Shakhdara River in Tajikistan

Pictured above: Samarskite-(Yb) specimen | Image credit: Raúl Jorge Tauber Larry, Public domain

Samarskite Healing Properties

As a mainly black healing stone, samarskite’s meaning reflects the grounding and protective properties of other black gemstones. It can be used as a root (base) chakra stone.

Historically, German-American homeopath Dr. Cyrus Maxwell Boger recommended samarskite in homeopathy for treating:

• Vertigo

• Slow metabolism

• Throat inflammation

• Excessive urination

• Hemophilia

In practical medicine, samarium is used for some drugs on cancer patients.

Samarskite Gemstone Properties

Since samarskite gemstones are quite rare, they lack standard grading criteria. We’ll still go over how the typical properties may apply to samarskite value:

• Color: Samarskite is usually black to brown, sometimes with yellowish-brown surfaces due to metamictization. Velvety black specimens are somewhat sought-after.

• Cut: Samarskite is sometimes cut into cabochons or faceted similarly to black gems like jet. Most often, it’s sold rough (uncut).

• Transparency: Most samarskite specimens are opaque, but thin, transparent fragments may be more valuable.

• Size: Massive samarskite material can yield large, opaque cabochons.

Speaking of masses, how does samarskite form?

Pictured above: Samarskite specimens from Canada | Image credit: Pacific Museum of Earth from Canada, CC-BY-SA-2.0

Samarskite Formation & Sources

Samarskite minerals form in pegmatites that contain rare-earths. As such, they’re often found with other rare minerals.

Commonly associated minerals include:

• Aeschynite

• Albite

• Beryl

• Biotite

• Columbite

• Garnet

• Magnetite

• Monazite

• Muscovite

• Tantalite

• Topaz

• Uraninite

• Zircon

Geographically, where is samarskite found?

Mining Locations

Samarskite-(Yb) is only known from Colorado and Montana, USA. The top source of samarskite-(Y) is Connecticut, USA.

Other notable sources of samarskite-(Y) are:

• Brazil

• India

• Japan

• Madagascar

• Norway

• Russia

• Zaire

• USA (Arizona, California, Connecticut, North Carolina, Virginia)

Pictured above: Bizarrely crystallized samarskite specimen from San Diego; Chuck Houser and Leo Horensky Collections | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Samarskite Price & Value

Faceted samarskite gemstones are around $30 to $40 per carat or roughly $80 to $100 total.

Rough samarskite ranges from $10 to $350, mostly based on the specimen’s size.

For just samarium, it costs around $5 per gram ($1 per carat).

Samarskite Care and Maintenance

First and foremost: samarskite minerals are often radioactive due to their impurities.

The amount of radioactivity depends on the specimen. That means you need to handle them with the utmost precaution. Follow our safety tips for handling radioactive gems.

For gemstone care, only keep samarskite for display. Store it in an enclosed container separate from other items.

Sold on Samarskite Stones?

Samarskite is a lesser-known mineral, but it’s full of value in terms of novelty, rare-earth elements, and rich history! With the proper precautions, samarskite would make a fantastic addition to any mineral collection!

Buy samarskite and other unique gemstones today!