Neptunite Gemstone: Properties, Meanings, Value & More

With their striking dark appearance and otherworldly moniker, it’s easy to assume that neptunite gemstones dropped out of space to enchant us with their allure.

Is neptunite rare? Indeed it is! What is interesting about neptunite is that it only occurs in a few places worldwide. In fact, it’s often found eclipsing California State’s official gem benitoite.

While not as rare as some other minerals, its unique structure, abyssal dark hues, and stunning shine make it a prized commodity among mineral collectors and crystal enthusiasts.

But neptunite possesses a captivating beauty that’s all its own!

Join us as we explore neptunite‘s properties, meanings, history, and more in our Neptunite Gemstone Guide.

Image credit: D. Nishio-Hamane, Flickr | CC-BY-SA-2.0

About Neptunite Stone

Neptunite owes its name to Neptune, the Roman god of the sea, for its resemblance to aegirine (named after Aegir, the Scandinavian sea god).

What are some other fun neptunite facts?

Neptunite in ‘Stardew Valley’ is a fictional representation of the real mineral in the popular farming simulation game, in which players use neptunite to complete various bundles and quests.

You can also use neptunite as an alternative zodiac stone for the Pisces sign in astrology.

So, what is neptunite made of?

Neptunite Specifications & Characteristics

Neptunite is a chemically complex semi-precious gemstone made up of sodium, potassium, lithium, iron, manganese, and titanium silicate.

Neptunite is classified as a member of the eudialyte group of minerals, which are complex silicates containing rare earth elements.

What is the Mohs hardness of neptunite? Similar to apatite, neptunite registers at about 5 to 6 on the Mohs scale. It’s a relatively durable mineral that’s hard to scratch or damage.

The mineral is also piezoelectric, generating an electric charge in response to mechanical stress or pressure. This makes it potentially useful for scientific or technological applications, like in devices that convert mechanical energy into electrical energy.

Here’s an overview of neptunite’s mineral traits:

• Chemical formula: Na2KLiFe2+2Ti2Si8O24

• Mineral family: Silicates - Inosilicates

• Mohs hardness: 5 to 6

• Color: Black with dark maroon highlights; Dark brown to dark brownish-red.

• Crystal structure: Monoclinic

• Luster: Vitreous

• Transparency: Opaque, with slight translucency on some edges

• Refractive index: 1.69 to 1.74

• Density: 3.19 to 3.23

• Cleavage: {110} Perfect

• Tenacity: Brittle

• Streak: Cinnamon-brown

• Pleochroism: Visible (yellow-orange to orange to deep red)

• Birefringence: 0.029 to 0.045

• Dispersion: Strong (can exhibit rainbow-like effects)

Shifting our focus to the past, when was neptunite discovered?

Pictured above: Naptunite crystal on white natrolite | Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Neptunite Meaning & History

Neptunite is a fairly recent mineral, having been discovered in 1893 by a group of American mineralogists led by George F. Kunz in San Benito County, California.

However, some sources suggest it may have been found in West Greenland first.

Since the mineral was found around the 1900s, there aren’t any known ancient uses for neptunite. That said, its locality in California boasts a rich mineral mining and exploitation history. Therefore, it’s possible that Native American tribes in the area collected neptunite before European settlers arrived.

While it’s not known for any industrial applications, various fields have used piezoelectric materials like neptunite due to their ability to convert mechanical stress or pressure into electricity. However, because of neptunite’s relative rarity, its piezoelectric properties aren’t as well-studied as more common piezoelectric materials, like quartz or lead zirconate titanate (PZT).

Metaphysically, what is neptunite used for?

Image credit: James St. John, Flickr | CC-BY-SA-2.0

Neptunite Healing Properties

Many believe neptunite is a healing stone imbued with incredibly strong vibrations — so much so that you may experience a defensive response to its energy. Similar to moldavite, it’s not unusual to feel a sense of discomfort or disconnection when first working with neptunite.

Crystal healers advise that even experienced practitioners may need time to acclimate to neptunite’s potent energies. If you feel uneasy when first working with neptunite, they suggest giving it a break and gradually working it into your routine for a more gentle integration of its effects.

Emotional Healing

Black gemstones like neptunite represent the delicate balance between light and dark, life and death, and good and evil. This symbolism extends to its emotional healing abilities.

For instance, neptunite is said to assist in rediscovering lost connections, both within yourself and with others.

Some suggest neptunite promotes self-awareness, helping you better understand your needs and desires. Hence, its ability to foster deep connections and inspire a greater sense of harmony and fulfillment.

Chakra Healing

You can harness the energy of some gems as chakra stones to keep your energy centers in balance.

Neptunite is believed to support all chakras within the body, making it a powerful stone for chakra alignment and activation. Its energy helps stimulate and realign any chakras that may have become dormant or imbalanced over time.

Now let’s see how neptunite gems are graded.

Pictured above: Black neptunite and blue benitoite crystals on white natrolite| Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Neptunite Gemstone Properties

Gems undergo grading to determine their quality, rarity, and overall value. This more accurately pertains to gems for use in jewelry.

Neptunite is unique in that it’s not typical for jewelry applications. Instead, neptunite is primarily a collectors’ specimen. That said, some neptunite gems do exist, albeit extremely rare.

In such cases, experts grade neptunite gems based on color, cut, and carat weight or size.

Color

Neptunite commonly occurs in dark black to reddish-brown with a glass-like luster.

What color is neptunite’s most expensive hue? The most desirable and valuable neptunite specimens are those with a deep, rich black coloration free of brownish or reddish tones.

Since neptunite is pretty much opaque, any inclusions or internal characteristics typically aren’t visible despite how it’s cut.

Cut

While neptunite can be cut and polished into small gemstones, these are relatively rare and not widely available.

When neptunite is cut and faceted, it’s typically done so in a way that enhances the stone's natural color and luster.

As a collectors’ stone, you’ll likely find neptunite showcased in its rough, natural form.

Carat Weight & Size

The size range of extracted neptunite varies depending on the specific deposit and location where it's found. However, neptunite crystals are usually small to medium in size, with the largest known ones measuring up to a few centimeters in length.

Being extremely rare, the size of faceted neptunite varies. Most are incredibly small, but some gems have reached 15 ct.

Rough neptunite also comes in a range of sizes, with larger and more well-formed crystals generally being considered more valuable.

Moving on, how is neptunite formed?

Pictured above: Black neptunite and blue benitoite on white natrolite | Image credit: Parent Géry, CC-BY-SA-3.0

Neptunite Formation & Sources

Neptunite’s formation is still being studied today, but here’s what we know.

The mineral usually forms in hydrothermal veins altered by high-temperature fluids — often associated with other minerals like natrolite, albite, or joaquinite.

As an eudialyte member, neptunite’s formation is typically associated with environments rich in sodium, potassium, titanium, and iron; it’s believed to occur when these elements combine with silica and other minerals under high-temperature and high-pressure conditions.

How do you get neptunite? It’s usually extracted through mining from locations where neptunite occurs. In fact, it’s not uncommon to find neptunite locked in a contrasting snow-white natrolite matrix, making for a very attractive specimen.

Globally, where is neptunite found?

Mining Locations

The most significant locality for neptunite is in the Diablo Range, near the San Benito River in California. Virtually all collectors' specimens hail from this area.

Other notable localities include:

• Australia

• Brazil

• Canada

• Germany

• Greenland

• Hungary

• Ireland

• Libya

• Mongolia

• Namibia

• Russia

• Slovakia

• Tajikistan

Can’t wait to add neptunite to your collection? Let’s talk pricing.

Neptunite Price & Value

We’ve learned how rare neptunite is, but will it break the bank?

If you're lucky enough to come across faceted neptunite, you can expect to pay anywhere between $100 to $300 per carat.

Neptunite is more commonly available in rough or mineral specimens.

The pricing for rough neptunite ranges from around $10 to $50 per carat, but higher-quality specimens can far exceed that.

After splurging on neptunite, understanding how to care for your gemstone is essential for preserving its beauty.

Pictured above: Blueschist with fluorescing benitoite-neptunite-joaquinite-natrolite vein | Image credit: James St. John, Flickr | CC-BY-SA-2.0

Neptunite Care and Maintenance

The good news is that neptunite is generally safe to handle, as it’s not considered toxic, radioactive, or otherwise dangerous.

Although neptunite’s a fairly durable mineral, it isn’t indestructible. So here are some tips for caring for your new gem:

1. To clean neptunite, use a soft brush, cloth, and soap-water mixture. Be sure to rinse thoroughly and dry with a soft rag.

2. Store neptunite in a soft cloth or pouch to protect it from scratches or damage.

3. Avoid exposing neptunite to harsh chemicals, prolonged sunlight, or extreme temperatures.

Get Lost in Neptunite’s Enigma!

Neptunite truly is a stone like no other, with its mysterious allure, deep color, and intriguing properties. But that’s not all — its powerful energy may be the key that unlocks your highest self, filling you with the deep fulfillment you’ve long been searching for.

Ready to tap into this enigmatic stone’s potential?

Buy neptunite and other striking gemstones today!