Holtite Gemstone: Properties, Meanings, Value & More

Holtite is a complex mineral in the dumortierite group only discovered in the past century. This stone is only somewhat known among collectors.

Is holtite rare? Absolutely. The mineral itself is very rare, and holtite gemstones are rare enough that they haven’t been seen on the market yet.

Among holtite’s notable properties are its high hardness (resistance to scratching) and complex formula that contains uncommon elements, including rare earth elements (REEs).

Intrigued yet? Then stick around to find out all about holtite’s mineralogy, history, benefits, and more!

Pictured above: Light pinkish-violet, platy holtite crystals from Murmansk Oblast, Russian Federation; Dr. Hartel and Ch. Rewitzer collections | Image credit: David Hospital, CC-BY-SA-4.0

About Holtite Stone

Holtite is an extremely rare semi-precious gemstone. It forms in mostly warm hues of creamy white, brownish-yellow, olive green, russet, or greenish-brown.

The only moniker for holtite is IMA1969-029, for when it was approved by the International Mineralogical Association (IMA).

Some mineralogists split holtite into two types: holtite I and holtite II, which have slightly different structures.

As of yet, scientists have not created synthetic holtite for either research or gemstone purposes.

Holtite Specifications & Characteristics

Holtite contains aluminum, antimony, arsenic, boron, hydrogen, iron, oxygen, silicon, and tantalum. As such, it has a few (notably complex) formulas. The formula approved by the IMA is (Ta0.60.4)Al6BSi3O18.

Other formulas used for holtite are:

• Al6(Ta,Sb,Li)[(Si,As)O4]3(BO3)(O,OH)3 + Fe, Be, Ti, Mn, and Nb

• (Ta0.60.4)Al6BSi3O18(O,OH)2.25

• (Al,Ta)7(Si,Sb)3(BO3)O12(O,OH)2.25

• (Si2.25Sb0.75)B[AI6(Al0.43Ta0.270.30)O15(O,OH)2.25

• Al6(Al,Ta)(SiO4,SbO4,AsO4)3(BO3)O3

The last one listed above was the originally proposed holtite formula.

Some of these formulas account for common impurities in holtite, of which there are many: titanium, iron, arsenic, niobium, manganese, beryllium, magnesium, calcium, lithium, sodium, potassium, rubidium, and caesium.

Like we said: complex!

The holtite mineral is in the dumortierite supergroup, which is divided into the dumortierite group, szklaryite group, and holtite group.

Besides holtite, the tantalum analogue, the other members of the holtite group are:

• Nioboholtite: Niobium analogue of holtite and titanoholtite; IMA formula (Nb0.60.4)Al6BSi3O18

• Titanoholtite: Titanium analogue of holtite and nioboholtite; IMA formula (Ti0.750.25)Al6BSi3O18

All three holtite group minerals are orthorhombic.

Both nioboholtite and titanoholtite are extremely rare, probably even rarer than holtite. Nioboholtite is only the second known mineral (after schiavinatoite) to contain niobium and boron as essential elements in its formula.

In terms of habits, holtite is found as acicular crystals forming compact pebbles, parallel needles, or blocky and pseudo-hexagonal crystals.

Holtite Properties:

• Mohs hardness: 8.5

• Color: Cream, beige, light buff (brownish ochre yellow), brown, olive green, greenish-brown, russet (dark reddish-orange brown)

• Crystal structure: Orthorhombic

• Luster: Vitreous or resinous; Dull when weathered

• Transparency: Translucent to semi-transparent

• Refractive index: 1.705-1.761

• Density: 3.60-3.90

• Cleavage: Distinct/good on {001}; Possible parting

• Fracture: Unknown

• Streak: White or light buff (brownish ochre-yellow)

• Luminescence: Fluorescence present - dull orange in SW-UV, bright yellow in LW-UV

• Pleochroism: Present in shades of yellow to colorless

• Birefringence: 0.015-0.025

• Dispersion: r < v

Pictured above: The open pit of the Greenbushes mine in Western Australia, seen from the public mine lookout; Taken January 16th, 2023 | Image credit: Calistemon, CC-BY-SA-4.0

Holtite History

The first discovery of holtite occurred in the early 1900s, when specimens were discovered in the Greenbushes Tinfield of Western Australia.

The original specimens, found among alluvial pebbles and up to 1 mm (around 0.4 in) long, were found as:

• Intergrown prismatic and needle-like crystals coating stibiotantalite

• Needle-like or asbestiform (flexible, thin, and long crystals forming a fibrous aggregate) crystals replacing tantalite

• Resinous pebbles made up of parallel needle-like crystals, many with S-shaped bends

M.W. Pryce of the Government Chemical Laboratories in Perth, Australia, wrote the first description of holtite and it was published in Mineralogical Magazine in 1971.

His description was based on alluvial stibiotantalite specimens donated in 1937 and 1943. Among the specimens first examined in 1962 was a fluorescent, unusually hard mineral he couldn’t identify at first.

In 1965, Pryce started studying the mineral and eventually found that it was a new mineral related to dumortierite.

Pryce named the new mineral “holtite” after Harold Edward Holt, the former Prime Minister of Australia who mysteriously disappeared while swimming at Cheviot Beach in 1967 and has since been presumed dead.

Discovery of Nioboholtite and Titanoholtite

In 2012, both nioboholtite and titanoholtite were discovered (along with holtite) within the “Szklary pegmatite” in the Lower Silesian Voivodeship of Poland. They were named for being niobium and titanium analogues, respectively, of holtite.

The first description of both nioboholtite and titanoholtite was published in 2013 by a group of men:

• Polish mineralogist Adam Pieczka,

• Canadian crystallographer Jim (R.J.) Evans,

• American mineral researcher Edward S. Grew,

• Canadian mineralogist Lee (L.A.) Groat,

• American nanomineralogist Chi Ma, and

• American mineralogist George R. Rossman.

That covers the historical side of holtite, but what can holtite be used for metaphysically?

Pictured above: Harold Edward Holt, former Prime Minister of Australia and namesake of holtite | Image credit: NAA, CC-BY-SA-4.0

Holtite Healing Properties

As a commonly cream to beige colored healing stone, holtite’s meaning reflects the cleansing and harmonizing properties of other white gemstones.

Brown holtite stones have the grounding and protective properties of brown gemstones, while green holtite crystals have the relaxing and hope-boosting properties of green gemstones.

Physical Healing

Physically, holtite is believed to treat issues related to:

• Pregnancy

• Digestion

• Nausea

• Skin disorders

• Epilepsy

• Carpal tunnel

• Inflammation

Emotional Healing

Emotionally, holtite is believed to help relieve negative feelings like worry, anger, or resentment. It’s said to boost mental clarity and creativity, helping you embrace self-expression while dispelling deep emotional wounds that may be holding you back through self-doubt.

Crystal healers also recommend holtite for providing protection, grounding, focus, and resilience.

Chakra Healing

Chakra healing involves opening or balancing a specific energy center (chakra) that’s been blocked. Holtite is a chakra stone for the root (or base) chakra.

The root chakra governs fundamental needs like safety and belonging. When it’s blocked, feelings of uncertainty, anxiety, and detachment may arise. Opening it with holtite can bring in feelings of connection, grounding, and stability.

Holtite Gemstone Properties

Unlike most other gemstones, holtite doesn’t have grading criteria given its extreme rarity.

We’ll still touch on how each of the standard grading properties may apply to holtite value:

• Color: Holtite stones vary mostly in shades of light brown and green. More interesting colors like olive green, along with evenly colored stones, may command higher prices.

• Cut: As of now, holtite has not been faceted. Some material could be cut into cabochons, but any cut holtites aren’t common. Most holtite for sale is rough (uncut).

• Clarity & Transparency: Holtite crystals with higher transparency (and fewer visible inclusions) will carry higher value.

• Carat Weight: Holtite cabochons have the potential to be up to around 1 in (2.54 cm) long. Most distinct holtite crystals are only up to 2 cm (around 0.79 in) long.

Pictured above: Szklary pegmatite where holtite has been found; Description: Hybrid pegmatite (desilified) with tourmalines and feldspars. Szklary near Ząbkowice Śląskie (nickel mine "Marta"). Lower Silesia, Poland (translated from Polish) | Image credit: Piotr Sosnowski, GNU Free Documentation License

Holtite Formation & Sources

Holtite is only found in a few places that have all the necessary elements for its formation. It’s been found in unique pegmatites (like the Szklary pegmatite in Poland), as coatings on stibiotantalite, in alluvial tin deposits, and as a replacement of tantalite.

Commonly associated minerals found with holtite are:

• Amphibolites

• Cassiterite

• Quartz

• Microlite

• Stibiotantalite

• Tantalite

• Tantite

• Tourmaline

That’s where holtite is found geologically, but geographically, where does holtite come from?

Mining Locations

Currently, there are only four known localities where holtite has been discovered:

1. Argentina (San Luis Province)

2. Australia (Western Australia)

3. Poland (Lower Silesian Voivodeship)

4. Russia (Murmansk Oblast)

The most prominent locations are Australia and Russia.

Holtite Price & Value

Holtite is so rare, it’s hardly ever seen on the market.

When it does show up, it’s usually holtite as a rough specimen in a matrix, often accompanied by other minerals.

These rough specimens range from $50 to $125 each.

Pictured above: Large, solid, pure antimony nugget - example of toxic material present in holtite | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Holtite Care and Maintenance

Despite being quite high in hardness, holtite is rarely faceted in part because of its medium-risk toxicity. This risk comes from the presence of arsenic and rare earth elements like antimony.

For arsenic, the biggest risk for exposure is ingestion. Antimony is also dangerous if ingested, such as breathing in the fibers of antimony dust.

Usually, touching rocks or minerals containing arsenic isn’t a big risk, but it’s still best to be cautious. Follow our safety tips for handling toxic gems and keep holtite away from anyone who might put it in their mouth (like pets or children).

You can safely wear holtite jewelry without worrying about many items scratching it, given its hardness. But if you want to be extra cautious, keep it in a display case.

In terms of gemstone care, keep holtite away from other stones to avoid scratching the other gems. Clean holtite with warm water, mild soap, and a soft toothbrush.

Harmonize Your Energies with Holtite!

Holtite may be rare, but this only adds to its allure — along with its unique formula, warm colors, and metaphysical benefits. This grounding, protective, and harmonizing crystal is a great way to make any space as peaceful as possible.

Buy holtite and more gorgeous gemstones today!