Bort Gemstone: Properties, Meanings, Value & More

bort gemstoneBort is a type of diamond that isn’t high-quality enough to be a gemstone. Instead, it’s used industrially or in the gemstone industry for working with gem-quality diamonds. 

So, is bort a type of diamond? Yes, though bort is often shards or powdered forms of low-quality diamonds. Most bort crystals are dark and opaque. 

Today, we’ll go over everything you need to know about this stone, from bort’s hardness to history and properties to prices. 

bort gemstone

About Bort Stone

The bort mineral may be called bort, boart, or boort. One old name for a type of bort is ballas, though this may also be considered a bort or diamond variety. Other industrial nicknames for bort include “crushed diamond” and “industrial grade diamond.” 

A diamond is a precious gemstone, so one could argue that bort is also a precious gem. However, you’ll hardly ever see bort diamond jewelry or faceted bort stones on the market for gem purposes the way you will with diamonds.

That said, bort and diamond are still the same material, making bort an April birthstone and Aries zodiac stone. Astrologically, bort helps the similarly hard-headed Aries by tamping this sign’s impulsivity and giving them some mental clarity. 

Additionally, this diamond variety is technically a commemorative 60th and 75th wedding anniversary gemstone. Though diamond was traditionally only for the 75th anniversary, Queen Victoria I added it for the 60th anniversary in 1897 (her 60th year on the throne) to commemorate her own “Diamond Jubilee.” 

You can also use bort or diamonds to celebrate non-wedding anniversaries too! Metro-Goldwyn-Mayer (MGM) did it in 1984 and Disneyland did it in 2015, so why not? 

Bort is actually the most common type of diamond currently mined in the world, making up roughly 70 to 80 percent of all diamonds mined.

Industrial Uses of Bort

The main uses for bort are gemstone cutting and power tools. Since diamond is the hardest material, bort can scratch (and therefore polish) other gemstones. Therefore, it’s used in grinding wheels and crushed to create abrasives for polishing gemstone facets. 

In more general industries, small bort crystals are used for drill bits and other cutting machinery like saws. This protects the tool’s edges, making it last longer, and allowing them to efficiently get through difficult materials, like:

  • Rebar

  • Cement

  • Stones

  • Concrete

  • Metals

Additionally, tiny bort particles mixed into lubricants (e.g. paraffin oil) aren’t suspended in the liquid, lowering the liquid’s friction by up to 50 percent compared to the friction of the liquid without the bort particles.

“Crushing bort” is the term for bort that gets crushed (big shocker there) and used in grits for abrasion. 

Given its industrial strength, is bort stronger than diamond? The tenacity/toughness (a material’s resistance to breaking or fracturing) of both diamond and bort is brittle. Unlike diamonds, however, bort lacks perfect cleavage, so it won’t split as easily from a hard blow. 

Speaking of qualities like tenacity, let’s discuss bort’s mineral properties.

bort diamond dust mirrorPictured above: Diamond dust on mirror | Image credit: Granger Meador, Flickr

Bort Specifications & Characteristics

First, what is bort made of? As a diamond, bort is purely made of carbon with the simple formula of C (for, you know, carbon). 

What color is bort? It depends on the form. When it’s crushed into powder, it’s often white to yellow. Shards can be yellow, brown, or black. Typically, bort is grayish to blackish in color. 

Considering diamonds are the hardest minerals, what is the hardness of bort? Bort usually has the same hardness (sometimes slightly lower) as diamond, ranking at 10 on the Mohs mineral hardness scale.

Bort’s crystallization is part of why it’s not used in gemstones. It often has radiating crystal growth, so jewelers can’t polish it. That means it maintains a greasy luster, as most diamonds must be polished to display their signature adamantine luster. 

Plus, bort usually has lots of inclusions, making it too unattractive to be a gemstone. 

Here’s the rest of bort’s mineral data, which slightly differs in some aspects from that of diamond:

  • Mohs hardness: 10

  • Color: Variable; Powder - white to yellowish, Shards - yellow, gray, brown, or black

  • Crystal structure: Cubic, though usually imperfectly crystallized

  • Luster: Greasy

  • Transparency: Translucent to opaque

  • Refractive index

  • Density: 3.5

  • Cleavage: None or poor

  • Fracture: Conchoidal

  • Streak: Colorless

  • Luminescence: Fluorescence & phosphorescence present - Blue in SW-UV & LW-UV

  • Pleochroism: None

Types of Bort

The only variety of bort is framesite. Framesite is a black, South African type of bort with tiny points of brilliance. What causes these sparkling points? It’s not 100 percent clear, but the sparkles likely come from tiny inclusions of diamonds.

Another diamond variety you may see pop up in discussions about bort is carbonado.

bort vs carbonado diamondsPictured above: Carbonado | Image credit: James St. John | Creative Commons Attribution 2.0 Generic license

Bort vs. Carbonado

Some gemologists consider bort and carbonado synonyms, but carbonado is slightly different. Carbonado is a brown, gray, or black diamond with resinous luster. Some call carbonado “black diamond.” 

Carbonado is massive and polycrystalline, meaning it has lots of crystalline portions pointing in random directions. This stone is also porous. 

However, carbonado and bort are both opaque and dark-colored. In terms of utility, bort and carbonado share similar industrial applications, as they’re both used for drills and abrasives. 

Shifting to the metaphysical side, let’s see what bort’s spiritual meaning has in store. 

Bort Meaning & History

Bort has the same symbolism of diamond, representing unbreakable bonds, faithfulness, and everlasting love. The spiritual meaning of bort also ties to strength, success, and inner beauty. 

The first diamonds came from Ancient India, which was the sole diamond source for about 1,000 years (starting around 300 BC). They used the Sanskrit term for diamond: Vajra, or “thunderbolt.” Locals believed diamonds formed by being struck by lightning sent by the god of storms, Lord Indra. 

Besides using them for religious and spiritually protective purposes, ancient Indians also created the first value grading guide for diamond quality: the Hindu scripture Garuda Purana

Origin of Bort

The name “bort” dates back to the early 1600s and derives from the Dutch boort. It specifically appeared in 1620, though the exact origin or writer is unknown. It’s translation may tie to the French term bort for “bastard” or the Dutch translation of boort, which is “drill.” 

Another possible explanation is from the Danish definition of bort: a type of edge or band. Many types of bort are chips that break off of diamonds while the gems are being faceted

Historical writings from the ancient Roman scholar Pliny the Elder reveal that uses for bort (before its name came around) may have been present in 1st-century AD times. 

While describing diamonds in Book 3 of his work Naturalis Historia, Pliny the Elder wrote:

“When, by good fortune, [diamond] does happen to be broken, it divides into fragments so minute as to be almost imperceptible. These particles are held in great request by engravers, who enclose them in iron, and are enabled thereby, with the greatest facility, to cut the very hardest substances known.”

undefinedPictured above: Jewish factories in Palestine on Plain of Sharon & along the coast to Haifa. Tel Aviv. Diamond works. Applying diamond dust on discs | G. Eric and Edith Matson Photograph Collection, Library of Congress | Public domain

Bort in Diamond Cutting

Diamond cutting didn’t begin until the 1300s, though this era only saw surface-level polishing for shine. Soon, Indian jewelers developed the first true diamond cutting technique using chisels.

In the 1400s, gem cutters realized they could use diamond dust to cut diamonds. Mary of Burgundy received the first diamond engagement ring from the Austrian Archduke Maximilian in 1477. 

One 1568 quote from Benvenuto Cellini, taken from his work The Treatises of Benvenuto Cellini on Goldsmithing and Sculpture, outlines the process of cutting with bort:

“Diamonds you can never cut alone, you must always do two at a time on account of their exceeding hardness, no other stone can cut them; it is a case of diamond cutting diamond. This you do by means of rubbing one against the other until a form is obtained such as your skillful cutter may wish to produce, and with the diamond powder that falls from them in the process, the final polish is subsequently given.”

Eventually, the Industrial Revolution and new technology allowed for increasingly elaborate faceted diamonds. Expanding markets and industries also allowed new uses for bort to emerge, like cutting tools used outside of the gemstone realm. 

Nowadays, bort is also seen in pop culture!

Bort in Pop Culture

The most prevalent reference to bort in popular culture is in the Japanese manga Land of the Lustrous, or Houseki no Kuni. Bort is one of the show’s characters. Like the other central figures, she is a gemstone humanoid. 

In the show, bort is a fierce fighter with diamond-class strength. Even Bort’s hair is evocative of the real-life stone, composed of many tails that reflect the numerous diamond particles inside bort. 

Personality-wise, Bort is a dark, serious, rough-and-tumble type. Meanwhile, the character Diamond is a bright, airy, happy-go-lucky type. Unlike Diamond, who is sparkling and decked out in large diamond crystals, bort is composed of tiny diamond crystals. That means bort can take harder hits with lesser damage.

bort gemstone rough crystalImage credit: Rob Lavinsky, – CC-BY-SA-3.0

Bort Healing Properties

Like diamonds and other gems, bort can function as a healing stone, and its powers are influenced by its coloring. Bort is primarily black, so it joins other black gemstones in offering protection, grounding, and commitment to spirituality. 

Unlike the popularly white gemstone diamond, bort is a chakra stone for the root chakra (rather than the crown chakra, like diamond). This means bort can open this chakra to bring you stability, protection, and security. 

Beyond chakra healing, bort’s healing properties are similar to that of diamond. Let’s look at those benefits below!

Physical Healing

Diamond varieties like bort are believed to treat the central nervous system (CNS) and improve cognitive abilities. Bort can also be used to amplify other crystals’ physical healing powers. 

Emotional Healing

The emotional healing benefits of bort include dispelling negativity and anxieties. The stone can also help facilitate personal growth, encouraging confidence and resilience. 

Speaking of growth, how does bort form? 

Bort Formation & Sources

Bort forms through the same process as diamonds, around 100 miles under Earth’s surface (in the mantle layer). Carbon deposits underground undergo extremely high pressure and temperature conditions, eventually crystallizing. This process may take days, months, or even millions of years. 

Miners find bort beside gem-quality diamonds, primarily in kimberlite rocks or nearby alluvial deposits. Other minerals in kimberlites include garnet, calcite, olivine, and pyroxene. 

Mining Locations

Currently, the primary producers of industrial-grade diamonds like bort are South Africa and Brazil. Other significant sources are Congo, Indonesia, and Russia. 

bort diamond gemstone polishing machinePictured above: Diamond polishing machine | Image credit: wim hoppenbrouwers, Flickr

Bort Gem Price & Value

As you might expect, the price of bort is significantly lower than the price of gem-quality diamonds. Large parcels of industrial-grade bort rough are typically around $3.50 per carat. Most individual bort stones are around $0.50 per carat. 

Synthetic bort powder is usually around $0.50 per carat or lower. Natural bort powder is only slightly higher, at $1-$2 per carat. Synthetic borts for diamond cutting are usually $0.25-$2.50 per carat. 

Bort dust-coated saws start at around just $2, while more heavy-duty equipment starts at $25 and can reach upwards of $500.

Find Spiritual Support with Bort!

Despite its possibly off-putting name, bort is a valuable material that has allowed gorgeous, beloved diamonds to grace the fingers of many a new bride for decades. Though it makes up most of the diamonds mined, bort is just fine being a key player in the background, reminding us that you don’t need awed recognition to feel satisfaction in your work!

If you’re interested in learning more about gemstone cutting, check out our guide on the basic tools and the fundamentals of lapidary work

Browse our collection of diamonds and other gemstones today!

Was this article helpful?

Search the Gemstone Encyclopedia

A-Z Of Gemstones

A-Z Of Gemstones

A-Z Of Gemstones
357 articles
Additional Gemstone Information

Additional Gemstone Information

Additional Gemstone Information
60 articles
Did You Know?

Did You Know?

Did You Know?
78 articles
Drawing Design Awards

Drawing Design Awards

Drawing Design Awards
2 articles
Gem Rock Auctions Verified Sellers

Gem Rock Auctions Verified Sellers

Gem Rock Auctions Verified Sellers
3 articles
Holistic Gemstone Information

Holistic Gemstone Information

Holistic Gemstone Information
34 articles
How To's

How To's

How To's is where you will find helpful articles from gem Rock Auctions on how to cut gemstones, select gemstones and buy gemstones.
9 articles


News and events on Gem Rock Auctions
48 articles
Technical Information on Gemstones

Technical Information on Gemstones

Technical Information on Gemstones
30 articles