Oct 2025

What is Gold Dore?

By StoneX Bullion

Believe it or not, gold doesn’t naturally exist in the form of high-purity bullion bars and coins. Before it reaches that stage, it needs to go through several steps that involve extracting, concentrating, and refining the precious metal from raw ore.

One of the most important steps in this journey is the creation of doré, a partially-refined gold bar that’s produced at the mine before being transported to a refinery. In this article, we share what to know about gold doré, including how it’s produced, how it differs from gold bullion, and why you should beware of dealers advertising gold doré for sale.

What is gold dore?

Gold doré (from the French word doré, meaning ‘golden’ or ‘gilded’) is a semi-pure alloy of gold and silver, usually produced at the site of a gold mine. It’s the first solid form gold takes after extraction and smelting, and still contains various impurities like copper, zinc, and other trace metals.

A typical gold doré bar contains between 50 - 90% gold, with the remainder mostly being made up of silver and other base metals. Because of its inconsistent purity, doré is not considered bullion and must still undergo further refining before it can be sold as investment-grade gold.

How gold doré is produced

Gold doré bars are usually created at or near mines where pure gold ore is extracted. This gives mining companies a way to consolidate their output into transportable and measurable units.

Here’s a look at the process of producing gold doré:

Mining & extraction: Gold-bearing ore is removed from the ground using drilling and blasting techniques
Crushing & grinding: The excavated pure gold ore is broken down into fine particles to release the gold from surrounding rock
Concentration: Different techniques, like flotation, gravity separation, or cyanide leaching, help concentrate the precious metals
Smelting: The concentrate is then heated in a furnace with fluxes like borax or silica, which help separate the precious metals from impurities
Casting: The partially-refined metal is melted and poured into moulds, forming solid gold bars, or gold doré
Marking: Once the molten metal bars have cooled, each is stamped with identifying details like its weight, estimated purity, and the mine’s mark.

Gold doré bars are usually produced from two main sources:

Mining operations, where ore is extracted, smelted, and partially refined on-site, and
Gold recycling operations, where high-purity scrap gold jewellery or electronic components are melted to form doré bars.

Learn More: How Gold Smelting Works

Characteristics of gold doré

Gold doré bars can look very different to the polished, uniform look of refined gold bullion. They often have rough, matte surfaces, and contain several different colours (e.g. yellow or greenish hues) because they’re still unrefined.

FEATURES & COMPOSITION OF GOLD DORÉ BARS
GOLD CONTENT	50 - 90% (average 70 - 80%)
SILVER CONTENT	5 - 40%
OTHER METALS	1 - 10% copper, zinc, lead, nickel, or trace platinum-group metals
WEIGHT	Usually between 5 - 25 kilograms
SHAPE	Roughly cast rectangular bars with uneven edges
COLOUR	Dull yellow to greenish hue

As you can see from the table above, there’s little consistency amongst gold doré bars. Each will reflect the unique mineral composition of the mine it came from – South African doré, for example, often contains around 10% silver. Doré produced from mining also tends to be less pure and more variable than doré produced from recycled gold.

See: Gold Purity, Fineness, And Karat – What Is It And How To Check It

What happens to gold doré bars?

Once gold doré bars have been produced, they’re sent to refineries where they’re transformed from semi-pure alloys into high-purity gold bullion products. The purpose of refining is to remove every last trace of other metals to achieve a purity of 99.5% to 99.999%.

The gold refining process

There are a few different methods used to convert doré into investment-grade gold products:

The Miller process: The Miller process involves bubbling chlorine gas through molten doré. The chlorine reacts with base metals like silver, copper, and zinc, to form chlorides that rise to the surface and are skimmed off. This technique is fast, efficient, and cost-effective, able to produce gold with a purity of around 99.5%. It’s often used as the first step in refining before moving onto further purification methods.
The Wohlwill process: The Wohlwill process is an electrolytic technique that’s used to produce higher-grade bullion. Here, gold is dissolved into an acid solution then subjected to an electric current that causes pure gold to deposit onto a cathode, while impurities remain in the solution or settle as sludge. The Wohlwill process can produce gold up to 99.999% purity, which is the highest commercially achievable standard.
The Aqua Regia process: The Aqua Regia process is a traditional chemical method that uses a mixture of hydrochloric acid and nitric acids to dissolve gold. Once it has been dissolved, the gold can be re-precipitated and purified to about 99.9% purity. This is a more time-consuming process, but it’s still often used in jewellery recycling and artisanal refining operations.

The end result is pure, high-quality gold bullion that’s then cast into gold coins, gold bars, or other investment-grade products.

Note that even through these techniques, it’s impossible to achieve 100% pure gold. To date, the highest recorded purity ever achieved was 99.9999% (six nines fine) by The Perth Mint in 1957.

Keep Reading: Gold Alloys Guide – Composition, Types & Uses

Gold doré vs gold bullion

Gold doré and gold bullion are produced at two different stages – doré is an unrefined, semi-pure form of gold produced after mining, while bullion is a highly-purified form of gold produced after refining.

Let’s take a look at how each of these gold products is different.

Gold doré

Gold doré is a rough alloy that contains a mixture of gold, silver, and base metals like copper, zinc, or lead. Its purity can range from 50% to 90%, depending on the source of ore and any refining done at the mine. Because it varies in composition, gold doré can’t be used to make jewellery or sold as an investment.

Gold bullion

Gold bullion, on the other hand, is a refined form of gold that meets strict international standards for purity, weight, and appearance. It’s the form of gold that’s used by investors, institutions, and central banks around the world for investment.

Gold classified as bullion must have a minimum purity of 99.5% (995 fineness), although most bars and coins are refined to 99.99% or even 99.999% purity. To verify this purity, authentic bullion products come with assay certificates and serial numbers.

Gold doré vs gold bullion

The table below shows the differences between gold doré and gold bullion:

	GOLD DORÉ BARS	GOLD BULLION BARS
PURITY	50 - 95% (variable)	99.5 - 99.999% (consistent)
COMPOSITION	Gold, silver, other base metals	Nearly pure gold
APPEARANCE	Rough, irregular bars with varying hues	Smooth bars or coins with consistent colour
TRADING	Not suitable for investment or trading	Traded in global markets

Can you buy gold doré bars?

Even though gold doré ingots aren’t suitable for investment, you can sometimes see them advertised for sale (often listed as ‘unprocessed raw gold’). We highly caution against purchasing these gold products, even if their prices seem appealing, and you will never see them stocked by reputable precious metal retailers.

Here’s why gold doré bars aren’t suitable for investment:

They lack standardisation, which means every bar has a different composition so you don’t know exactly what you’re buying
They’re not certified or hallmarked by recognised refineries, so there’s no guarantee of purity or authenticity
You cannot trade them on global markets or resell them easily.

For these reasons, they rarely, if at all, make reasonable investments for portfolio diversification or wealth preservation.

On top of that, there is also the risk of fraud when buying gold doré online. In 2022, consumer watchdogs like Stiftung Warentest reported that two Swiss firms had been promoting dubious raw gold investments through online advertising and glossy marketing materials.

These companies claimed to offer customers a chance to buy raw gold that would be stored in Swiss refineries until refined and sold for a profit. In return, customers were guaranteed high annual returns as the gold increased in value. There are lots of issues with schemes like this:

Firstly, the process of refining gold is extremely costly and would eat into the customers’ profits
Guarantees of profits should never be made, especially considering gold’s price can fluctuate depending on supply and demand
Customers never actually ‘owned’ the physical gold promised to them
It’s unclear exactly how securely the gold would be stored.

At the end of the day, this kind of contract actually locks customers into much higher costs than if they were to simply buy purified, authentic gold bullion at a higher price from the get go.

What’s the difference between gold doré and raw gold granules?

Since gold doré is sometimes advertised as raw gold, there can be some confusion between actual raw gold granules and unrefined gold products.

Unlike doré bars, which are partially-refined bars of gold, gold granules are tiny, bead-like particles of extremely pure gold, with a typical fineness of 99.99%. They’re made by pouring molten gold through a sieve into cold water, which causes the metal to form small droplets that solidify instantly.

Granules aren’t typically sold for investment purposes. They’re mostly used to manufacture jewellery, produce gold coins and bars, or in industrial or laboratory applications.

Buy authentic gold bullion products

If you want to invest in gold safely, the only way to do so is through authentic gold bullion bars and coins produced by trusted mints and refineries. At StoneXBullion, we source our bullion directly from accredited producers. This helps us ensure the highest international standards of purity and authenticity while still offering some of the most competitive prices on the market.

Browse our selection of investment-grade gold bullion bars and coins and start preserving your wealth with gold today.