All About Bornite – Uses, Properties, Color, and Worth
Bornite is a sulfide mineral that can be found in igneous, metamorphic, and sedimentary rocks. It is considered to be an ore of copper. Bornite is often called “peacock ore” by many due to its array of similar colors you might see on peacock feathers.
Bornite, or peacock ore, is not man made but instead is a natural occurrence on our earth. This man made notion comes about due the ability to treat chalcopyrite, with chemicals, to look much like bornite and then call it peacock ore.
Many will say peacock ore is bornite. There are also those that will say only treated chalcopyrite is called peacock ore. I am on the former of the two notions and I intend to use both bornite and peacock ore interchangeably.
Bornite was first made known in 1725. It was found in the Krusne Horny Mountains of the Karlovy Vary Region, Bohemia which is now known as the Czech Republic. It was later named by an Australian scientist Ignaz von Born, hence the name bornite.
The Uses of Bornite
Bornite has few uses and is mainly used as a specimen for a rock collectors. Most bornite specimens are used for display in homes, offices, or other locations as an eye catching piece. Some bornite will be used as cut out cabochons for jewelry such as necklaces…
Cutting out bornite is not an easy task. It is soft coming in at a 3 on the Mohs scale of hardness so jewelry with this mineral is rarely seen.
Some believe that while carrying or wearing peacock ore, it will have meaning or specific healing benefits. These proposed healing benefits and meaning range from having increased happiness and joy, to being able to diagnose and find negative energies. These negative energies can then be filtered out of your body.
Such concepts can draw some controversy from some. Many can find fact that when looking at one of these beautiful specimens of bornite, that a little increase in happiness and joy may just be possible.
For the most part, bornite does not have very many uses in every day life but than that of eye appeal.
Some Common Bornite Properties:
 | |
| Bornite Scale Mohs Hardness: | 3 |
| Specific Gravity: | 5.0 – 5.1 |
| Bornite Streak: | Grey-Black |
| Fracture: | Uneven to Conchoidal |
| Bornite Luster: | Metallic |
| Crystal System: | Orthorhombic |
| Bornite Chemical Formula: | Cu5FeS4 |
| For further bornite data and properties: | Mindat.org |
The Colors of Bornite
Bornite has a brown to reddish brown color before it is exposed to the air. Its color will then change after this exposure to the elements. After exposure to air, bornite has a purple, blue, red, or even black color that will often have a metallic luster.
The eye appealing metallic colors are formed from the iridescent tarnish that forms when exposed to the air. The varying thickness of this formed tarnish will determine the color that is seen. The colors are shown when light refracts between the surface of the mineral and the top of the tarnished layer.
Opal expresses a similar light refracting occurrence as bornite. Light from the spectrum will filter at different distances of space and silica bubble sizes when it comes to opal.
The varying colors are often intermixed showing quite a beautiful display of different colors rather than just one color. When inclusions of chalcopyrite are present, which is common, you can also expect to see some greens and yellows in the mix.
In many cases chalcopyrite will be treated with acids to give it the rich blues and purples you may not see in raw bornite. Be wary if someone attempts to sell you bornite, even calling it “peacock ore”, as there is a high possibility it could actually be chalcopyrite treated with these acids.
Is getting fooled by this little possibility of deception really a big deal? Maybe only to those that want a specimen of bornite and not an acid treated chalchopyrite specimen. The main image for this article holds some suspicion on if it is real bornite.
What is Bornite worth?
The worth of bornite is very minimal due to its abundance and it not being a rare mineral. Bornite will increase in value as a specimen due to size, color, and uniqueness. Bornite will also increase in worth if you have a rare crystal specimen.
Most bornite will range in at under $10 USD for a sample specimen. Rock collectors going after larger specimens will start to pay over this price. You can expect the prettier the color, the more it will cost past that.
Attribution: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Usually some of the pricier specimens of bornite will also have chalcopyrite with it. The array of colors are quite appealing to the eye and some of these larger specimens can take you well over $100 USD.
I often do see a raw piece of bornite attached to a pendant as a necklace. The price on these can vary based on the metal that was used and can often come in under $50 USD.
Bornite Formation
Bornite is formed as a hydrothermal precipitate at lower heated temperatures. This mineral will undergo an enrichment process closer to the earth’s surface. This enrichment process is called the supergene process unlike the hypogene process which occurs deep below the earth. Temperatures below 200 degrees Celsius will form most of the available bornite we see today.
It is possible in rare occurrences to have formed bornite crystals. Isometric bornite crystals can form when temperatures are above 228 degrees Celsius. These crystals are usually misshapen cubes with curvature on the face part of the cube.
Bornite crystals can form in even more rare occurrences of octahedrons and dodecahedrons. These are 8 to 12 sided crystals. As bornite cools, crystals will be formed from the more atomically ordered elements of iron and copper.
Toxic Peacock Ore
As an ore of copper, peacock ore will have a high content of copper, which is about 63 percent. With so much copper available, along with sulfur, many would say bornite, or peacock ore, is toxic. If you handle with care and don’t ingest it, toxic exposure will be negligible.
The toxicity of this mineral is currently not enough to make it on the list of highly toxic minerals. If you want to do a little reading on some highly toxic minerals, read my articles on “All About Cinnabar” and “All About Serpentine“. These minerals can be quite harmful to the human body.
Where can Bornite be found?
Bornite can be found in several places around the world including; Africa, Australia, Bolivia, Canada, Namibia, Mexico, and in the USA states of Arizona, Colorado, Connecticut, and Montana. Larger bornite crystals have been found in Tirol Austria in what is called the Frossnitz Alps.
Other notable places bornite crystals have been found are Dzhezkazgan, Kazakhstan, Shaba, Congo, Mhangura, Zimbabwe. Some of the lesser areas where crystals have been found can be Connecticut and Montana USA.
Some commonly associated minerals with bornite are magnetite, pyrite, chalcopyrite, covellite, malachite, and azurite as these minerals contain copper or iron.
For some comparison to bornite, I have written some good articles on some of these minerals.
“All About Pyrite” (Can you tell the difference between pyrite and gold?)
“All About Malachite” (The patterns on this mineral are awesome, it makes a great specimen)
“All About Azurite” (This colorful mineral is one step away from becoming malachite. How?)
