Powellite Gemstone: Properties, Meanings, Value & More

Powellite is a commonly yellow to brown gemstone mostly known among collectors. The gem can also be vibrant green, nicknamed “chrome powellite.” It’s very similar to, and often confused with, scheelite.

In terms of rarity, powellite is an uncommon mineral, but for gemstones, it’s among the rarest. In fact, it’s one of the rarest, most sought-after gemstones from India.

Eager to know more? Then stick around to uncover all of powellite’s mineral and gemstone properties, along with its history, uses, prices, and more!

Pictured above: Unusually tan-colored, large powellite radiating cluster with good luster and translucence | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

About Powellite Stone

Powellite is a very rare semi-precious gemstone with variable colors, including yellows, greens, blues, grays, and even black or colorless.

The mineral is closely related to scheelite. So, what is the difference between powellite and scheelite? The main differences are their composition, fluorescence, and rarity:

• Composition: Scheelite is a calcium tungstate while powellite is a calcium molybdate.

• Fluorescence: Both usually fluoresce, but powellite typically emits a creamy yellow and scheelite emits a bluish-white.

• Rarity: Although rare, scheelite is still more common than powellite, including in faceted gemstone form.

Scheelite has various industrial uses as well, but what is powellite used for?

Powellite Uses

The most valuable aspect of powellite industrially is its molybdenum content.

Powellite is a minor ore of molybdenum.

Metallurgy makes up around 86 percent of molybdenum uses, specifically being mixed with other elements to create alloys like structural steel.

Some of molybdenum’s benefits in alloys include its temperature resistance, weldability, and corrosion resistance. Stable prices and lower densities make molybdenite a better alternative to tungsten sometimes.

Additionally, scientists have created synthetic powellite to study its mineral and chemical characteristics.

Speaking of which…

Pictured above: Cream-colored, fluorescent powellites forming giant composite crystal cluster under UV light; Charlie Key Collection | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Powellite Specifications & Characteristics

A calcium molybdate mineral, the formula for powellite is Ca(MoO4). Some write the formula as Ca(Mo,W)O4 to account for the common impurity tungsten (W).

Tungsten impurities are often present because powellite forms a series with scheelite, a calcium tungstate with the formula CaWO4. Sometimes, powellite molecules in scheelite can make the scheelite emit yellow fluorescence, when it usually emits whitish or blue fluorescence.

Under what group or chemical structure is powellite? Powellite has a scheelite-type dipyramidal structure and it’s in the scheelite mineral group.

Other members of the scheelite group include:

• Raspite

• Ronpetersonite

• Scheelite

• Stolzite

• Wulfenite

In terms of habits, powellite crystals are often pyramidal, typically with striated faces. Alternatively, the crystals can be flat and tabular to paper-thin on {001}. The mineral also occurs as masses, druzy, or crusts along with foliated, pulverulent (powdery), or ocherous (clay-like) aggregates.

Powellite properties listed:

• Mohs hardness: 3.5-4

• Color: Straw yellow, yellow, yellowish-brown, brown, greenish-yellow, greenish-blue, blue, blackish-blue, nearly black, gray, grayish-white, colorless; Sometimes color-zoned

• Crystal structure: Tetragonal

• Luster: Subadamantine, resinous, or pearly; Greasy on fractures

• Transparency: Translucent to transparent

• Refractive index: 1.967-1.985

• Density: 4.23-4.28; Varies with amount of tungsten impurities

• Cleavage: Indistinct/poor on {112}, {011}, and {001}

• Fracture: Uneven/irregular

• Streak: White or pale yellow

• Luminescence: Fluorescence present - creamy white, yellow, or golden yellow in LW-UV & SW-UV, dimmer under LW-UV

• Pleochroism: Visible in deeply colored specimens - blue to green (blue specimens) yellow to pale yellow (yellow specimens)

• Birefringence: 0.010-0.011

• Dispersion: 0.058 (strong)

Pictured above: Good, lustrous, cream-colored powellite crystal from India sitting on small matrix | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Powellite History

American chemist William Harlow Melville wrote the first description of powellite in 1890. His description was published in the American Journal of Science in 1891.

He named it in honor of Major John Wesley Powell, an American geologist, army soldier, explorer, and Director of the U.S. Geological Survey at the time, where Melville worked in the Chemical Laboratory.

Melville found the first powellite specimens in Idaho, USA, specifically the Peacock Mine located in the Seven Devils Mountains. He noted that bornite was most abundant there, but he found two associated minerals: a “lime-alumina iron garnet” (probably melanite) and an unknown mineral resembling scheelite.

Upon testing, Melville realized it wasn’t scheelite but a new mineral containing molybdenum. Notably, calcium molybdate hadn’t been seen in nature before this discovery.

In 1893, powellite’s second known locality was reported: Houghton County, Michigan. This discovery was written about by American chemist and mineralogist George Augustus Koenig and American geologist Lucius Lee Hubbard.

The first synthetic powellite created, a “lime molybdotungstate” was described by French geologist Auguste Michel-Lévy in 1894.

Powellite Healing Properties

As a commonly yellow healing stone, powellite’s meaning reflects the joyful and revitalizing properties of other yellow gemstones.

In energy healing, powellite is a beneficial crown chakra stone.

Other purported metaphysical properties of powellite include:

• Heightening spiritual awareness

• Increasing endurance

• Soothing tempers

• Boosting motivation

• Attracting good friends

• Promoting mental clarity

Pictured above: Extraordinary powellite crystal with complete, undamaged, huge floater crystal along with superb luster, sharpness, and multi-peaked terminations; Grown around stilbite crystal on one side | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Powellite Gemstone Properties

Many of powellite’s traits would make it a gorgeous gemstone, like its high dispersion , sometimes near-diamond luster, various attractive colors, and distinct pleochroism. But powellite’s scarcity and low Mohs hardness make these gemstones rare.

Still, besides rarity, powellite gems are still valued based on the standard color, cut, clarity, transparency, and carat weight.

Color

Most powellite is straw yellow to brown, often pale yellow. More valuable specimens are completely colorless, golden, greenish-blue or bright green.

Bright green powellite is nicknamed “chrome powellite” but the color likely comes from copper impurities, so some call them “cuprian powellites.” Greater amounts of copper oxide impurities lead to darker green powellite stones.

Some powellite specimens also display color-zoning, like blue to black zones.

Deeply colored specimens, particularly blue or yellow powellites, can also show distinct pleochroism (different colors at different viewing angles), raising their value.

Cut

Transparent, facetable powellite material is only known from one location — this combined with the stone’s softness makes faceted powellites rare and valuable. They’re usually cut into oval cushion shapes to bring out powellite’s fire and coloring.

Powellite is rarely cut into cabochons. Most powellite for sale is rough (uncut).

Clarity & Transparency

Clarity describes the degree of visible inclusions in a gemstone, which can lower its transparency and value.

Powellite can be eye-clean (no visible inclusions to the naked eye), which is most valuable, but some specimens are more translucent due to inclusions.

Potential inclusions in powellite include:

• Swirled structure

• Small paraniite-(Y) crystals

• Thorian monazite-(Ce)

• Black quartz

Powellite has also been found as an inclusion (with molybdenite) in quartz from Chile.

Carat Weight & Size

Powellite gemstones usually decrease in transparency with higher carat weights — highly transparent gems are typically 0.5 to 1 carat. However, translucent powellite gems have been cut into gems weighing over 15 carats. One faceted powellite weighs over 50 carats!

That said, most faceted powellite gems are under 2 carats.

Pictured above: Combination specimen of diamond-like, gemmy, honey-yellow, pseudo-octahedral powellite crystal on tiara-like cluster of snow-white scolecite blades accented with emerald-like, pastel-green fluorapophyllite crystals | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Powellite Formation & Sources

Most often, powellite occurs as a secondary mineral, formed when other (primary) minerals undergo oxidation.

As such, it’s found in oxidation zones of hydrothermal deposits containing molybdenum. The mineral can also alter into ferrimolybdite.

Rarely, powellite forms in basalts, granite pegmatites, and tactites.

Minerals commonly associated with powellite are:

• Molybdenite

• Ferrimolybdite

• Stilbite

• Laumontite

• Apophyllite

• Scolecite

• Fluorapophyllite-(K)

• Zeolites

Black powellite from Kazakhstan has also been found associated with uranium minerals like uramarsite (uranyl-arsenate mica).

Mining Locations

Geographically, where is powellite found?

The only known source of facetable powellite material in decent sizes is India, specifically Nasik. This locale is known for producing the best powellite worldwide.

Michigan, USA, is notable for producing cuttable blue powellite, but the material only yields very small gems.

Lastly, Chile is significant for somewhat recent finds of green cuprian powellite.

Other notable powellite sources are:

• Mexico

• Morocco

• Namibia

• Russia

• Turkey

• UK (England, Scotland)

• USA (Arizona, California, Nevada, New Mexico, Texas, Utah)

Pictured above: Sharp, fine crystal cluster of lustrous, unusually blue-green powellites, probably colored by celadonite inclusions; Charlie Key collection | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Powellite Price & Value

Perhaps unsurprisingly, faceted powellites carry the steepest prices, ranging from about $60 to $1,600 per carat or roughly $50 to $12,500 total. The highest prices go to high-quality and/or large gems.

Faceted cuprian powellite gems cost about $200 to $400 per carat or around $120 to $350 total.

The most valuable powellite rough tends to be attractive pink specimens on stilbite, which range from around $300 to over $30,000 each.

Individual uncut powellite crystals can range from $50 to $300, or over $700 if facetable.

Powellite Care and Maintenance

First, it’s important to know that powellite has medium-risk of toxicity because of its molybdenum content. Luckily, humans are only harmed by molybdenum when exposed to excess amounts, but it can be very toxic to specific animals like sheep and cattle.

Keep powellite away from anyone who might put it in their mouth, like pets or children.

In terms of gemstone care, keep powellite away from acids, especially hydrochloric acid and nitric acid. Be careful when handling it and store it away from other gemstones to avoid scratches.

We recommend only keeping powellite for display, as it’s too soft for jewelry.

Clean powellite carefully with warm water, mild soap, and a soft, microfiber cloth.

Pictured above: Lime-green powellite specimen with gemmy crystals in vug | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Power Up With Powellite!

Powellite is a rare gemstone, but this only adds to its allure, along with its beautiful colors, sparkle, and fluorescence. On top of that, it has some important industrial uses.

Powellite is a great addition to any collection or healing space that needs a boost of motivation and purpose!

Buy powellite and other beautiful gemstones today!