Jet Gemstone: Properties, Meanings, Value & More

Jet is a stark black or dark brown, lustrous gemstone with historical significance in jewelry and decor, though it’s not as popular today. Unlike most gems, jet isn’t a mineral or crystal, but it can still be faceted and carved into beautiful shapes.

Ever heard the phrase “jet black” before? It originated in reference to black jet stones!

Are jet stones rare? High-quality jet gemstones are rare, particularly the famous variety from Whitby, England.

By the end of this guide, you’ll know how to identify jet gemstones, what they’re made of, and what makes jet so special.

About Jet Stone

First, is jet a precious stone? No, jet is a semi-precious gemstone, though it’s been beloved for centuries.

Jet (or “lignite”) is a plant-based mineraloid, meaning it’s mineral-like. It’s also an organic gemstone alongside amber, pearl, and coral, as jet forms from wood decomposition. In fact, jet used to be called “black amber.”

The most similar gemstone to jet, however, is shungite, as both are black, carbon-based, and lightweight mineraloids.

Pictured above: Black onyx

Jet vs Onyx

At first glance, you may mistake jet for another gemstone: onyx, specifically black onyx. Are jet and onyx the same? No, jet and onyx are different.

How do you identify a jet gemstone vs an onyx gemstone?

Here are the differences:

• Classification: Onyx is a mineral; jet is a mineraloid.

• Composition: Onyx is a chalcedony variety (microcrystalline quartz) while jet is mostly composed of carbon.

• Color Source: Most solid black onyx has been dyed. Jet’s black color is natural.

• Hardness: Onyx is harder, ranking at 7 on the Mohs hardness scale compared to jet ranking at 2.5 to 4.

• Weight: Onyx is noticeably heavier than jet, with a density of 2.72 to 2.85 compared to jet’s density of 1.3 to 1.4.

• Streak: Onyx has a white streak in powdered form; jet has a brown streak.

That said, the similarities between the two mean you can use jet as an alternative mystical December birthstone. Jet itself is a zodiac stone for the sign Capricorn.

Jet Specifications & Characteristics

Since jet isn’t a mineral, its composition varies. But it’s always rich in carbon, with sulfur and iron as common impurities. Most jet stones are about 75 percent carbon, 12 percent oxygen, and 13 percent sulfur and hydrogen.

Sources differ on whether jet is a type of coal. Some call it an anthracite coal, others call it a subbituminous (lignite) coal. Others say it’s not coal but simply fossilized wood or a rock.

Regardless, the stone has two forms, hard and soft, that differ in the type of water involved in their formation. The terms could be considered misnomers, however, as both forms have the same Mohs hardness — soft jet is just more sensitive to temperature changes.

Jet is piezoelectric, meaning rubbing it can make it electrically charged.

Here’s a list of jet’s properties:

• Mohs hardness: 2.5-4

• Color: Black or dark brown

• Crystal structure: None

• Luster: Vitreous, resinous, or waxy; Sometimes metallic inclusions of pyrite

• Transparency: Semitranslucent to opaque

• Refractive index: 1.66

• Density: 1.30-1.40

• Cleavage: None

• Fracture: Conchoidal or uneven

• Streak: Brown

• Luminescence: None

• Pleochroism: None

Types of Jet

Jet has some trade names distinguished by where it came from, such as:

• Acoma Jet: Soft; Mined near Acoma Pueblo region of New Mexico, USA; Common in Southwestern Native American jewelry

• Erzurum Stone / Oltu Stone: Mined in eastern Turkey

• Spanish Jet: Higher sulfur content; Harder but more brittle; Mined in Spain

• Whitby Jet: Lower sulfur content; Mined in Whitby, England

Whitby jet is by far the most renowned type, known as the highest-quality jet available. These jet stones are found in the Whitby Mudstone Formation and formed roughly 180 million years ago from a tree similar to the Araucaria araucana (or “monkey puzzle”) tree.

In fact, most of the jet used historically was Whitby jet.

Pictured above: At an Antiques Fair at the NEC, the amazing exhibition of historic Whitby Jet objects and jewellery displayed by the W. Hamond company | Image credit: the justified sinner, Flickr

Jet Meaning & History

Jet stone’s spiritual meaning today is one of strength, protection, and purification. It’s often believed to bring good luck and mental clarity during stressful times.

Ancients believed jet stones provided protection from the evil eye, which represents a belief that someone’s ill intent towards you (often from envy) carries metaphysical consequences.

History

Archeological remains of jet gemstone jewelry have dated back to Neolithic times (10,000 BC to 2,200 BC) in ancient Britain and the Bronze Age (3,300 BC to 1,200 BC) in Roman, Viking, and Saxon artifacts.

For centuries, jet was called “lignite,” derived from the Greek gagates lithos, meaning “stone of Gages.” Gages was a Lycia river and town in Asia Minor.

Ancient Romans (625 BC to 476 AD) used Whitby jet in rings, pendants, hair pieces, and decor, believing the stone provided mystical protection.

Folks in Medieval times (476 AD to 1450 AD) first called jet “black amber” or “gagates” in Materia Medica lapidary texts. The term “jet” came soon after, derived from the 12th-century French term jaiet.

Jet popularity soared in the Victorian Era (1837 to 1901).

Whitby jet was introduced to the public at the Great Exhibition of 1851, becoming a staple souvenir for tourists that led to the first Whitby jet store opening in 1860. But most of its popularity came after Queen Victoria wore carved jet mourning jewelry following Prince Albert’s death in 1861.

Nowadays, what are the benefits of jet stones?

Image credit: Auckland Museum

Jet Healing Properties

Today, jet as a healing stone goes beyond a mourning accessory. Like other black gemstones, jet offers protection, grounding, and positivity, especially when used as a root chakra stone.

Physical Healing

Touted physical jet gemstone benefits include treating:

• Migraines

• Inflammation

• Menstrual cramps

• Hormone imbalance

Emotional Healing

Emotionally, jet can help you gain clarity on habits or thought patterns that don’t benefit you. It’s also said to provide emotional strength and turn negative energies (internal or external) into positive ones.

Jet Gemstone Properties

Is jet stone valuable? Jet’s value depends on its properties, namely color, cut, luster, and authenticity. Carat weight isn’t as important, since jet is lightweight enough to be fashioned into virtually any size.

Color

Jet’s color can range from brown to black, with stark black jet stones being most valuable. Some specimens even display the structure of the wood they formed from.

Cut

Jet can be cut into faceted shapes, but it’s more often carved. Simple carvings are easy, but intricate carvings require greater skill. Cameo and intaglio carvings are common, especially in antique jet jewelry.

Other options include cabochons, beads, or inlay.

Luster

Jet usually polishes well, with a bright luster. But jet gems with greater luster are more valuable.

Simulants

Jet’s rarity means simulants are common. In fact, “French jet” is actually a black glass. Typical jet simulants are:

• Plastic

• Black glass

• Obsidian

• Black tourmaline

• Chalcedony

Now, how does real jet form?

Image credit: Geni | Creative Commons Attribution-Share Alike 4.0 International, 3.0 Unported, 2.5 Generic, 2.0 Generic and 1.0 Generic license

Jet Formation & Sources

Jet formation takes thousands to millions of years. Part of a tree branch — usually from the Araucariaceae family of Jurassic and Cretaceous times— sinks to the bottom of a body of water, where it’s covered by sediment.

Over centuries, the woody material is gradually compressed, degraded, and heated, compacting into a fossilized material.

The type of water matters, too. Hard jet forms in salt water, while soft jet forms in fresh water.

Mining Locations

England is the top source for high-quality jet gemstones, with Spain in second for commercial production.

Other jet sources include:

• Austria

• Cambodia

• Canada

• France

• Germany

• India

• Italy

• Luxembourg

• Mongolia

• Poland

• Portugal

• Russia

• Turkey

• USA (Colorado, New Mexico, Utah)

Sources aside, how much is jet worth? It’s more affordable than you’d think.

Jet Gemstone Price & Value

Is jet expensive? Not as expensive as you’d think. While carved antique jet jewelry can go for $300 to $1,000, most jet gemstones are around $0.40 per carat ($2 per gram).

Here at Gem Rock Auctions, you can find large jet carvings for around $0.30 per carat.

Our jet beads are available for under $1 per carat ($14 to $50 for a set).

Modern Whitby jet jewelry can be pricier, given its quality, with pendants costing around $100 to $150.

Jet Care and Maintenance

Last, we’ll discuss gemstone care.

Are jet gemstones fragile? Jet is fairly fragile, with a brittle tenacity (easily broken or crushed) and pretty low hardness. We recommend getting protective settings for jet jewelry, especially more vulnerable types like jet rings or bracelets.

You can clean jet with warm water, mild soap, and a soft toothbrush. Store it separately from other gemstones.

Keep jet gemstones away from:

• Perfumes or cosmetics

• Harsh chemicals

• Mechanical cleaning systems (e.g. steam, ultrasonic)

Feel Like a Jet Setter in Jet Jewelry!

Jet gemstones may not hold the popularity they did in Victorian times, but this subtle black gemstone is the perfect jewelry piece. Not only can it provide positivity and protection, its lustrous, neutral appearance complements any outfit!

Buy jet gemstones today!