Gold Purity: What the Numbers 375, 585, 750, 925, and 999 Mean and How to Check Authenticity

Gold purity is an official marking that indicates the amount of precious metal in a jewelry piece or bullion alloy, and it is precisely this value that determines the item’s worth, color, and resistance to wear. Numbers such as 375, 585, 750, 925, or 999 stamped inside a ring often raise questions even among experienced jewelry buyers.

The challenge is that the market also contains Soviet-era markings (for example, 583) and silver purity marks (925), which are easily confused with gold. In addition, purity is expressed in different formats: karats, percentages, or thousandths, making it useful to have one clear comparison system.

Below you will find a detailed explanation of each of the most common gold purity standards, a complete purity chart with karat and percentage equivalents, and practical ways to verify jewelry authenticity both at home and through professional testing.

What Is Gold Purity and How Is It Measured in Karats?

Gold purity indicates the amount of pure gold in an alloy, expressed in thousandths (the millesimal system). For example, 585 purity means 585 parts pure gold out of 1000, or 58.5%, or 0.585. These are simply three different ways of writing the same value, which is why any of these formats may appear stamped on jewelry.

A similar principle applies to investment gold: 999 means 99.9%, while 999.9 (or .9999) means 99.99%. These are different levels of precision, not synonyms.

Pure gold is too soft for everyday jewelry, which is why it is alloyed with other metals. Copper gives a reddish tone and added strength, silver and palladium create a lighter color, while zinc lowers the cost and improves casting properties. Thanks to these additions, jewelry retains its shape, resists wear, and acquires its characteristic color.

The karat system expresses purity in twenty-fourths: 24K corresponds to pure gold. Conversion is simple, for example: 14K × 1000 / 24 ≈ 585.

The most common equivalents are:

• 9K = 375

• 14K = 585

• 18K = 750

• 22K = 916

• 24K = 999

Lithuania and the rest of the EU use the millesimal system, while the United States and the United Kingdom mainly use karats. This is why imported jewelry may carry both markings, for example “14K 585.”

At the state level, gold purity is certified by the Lithuanian Assay Office, which performs precious metal testing and marks jewelry with an official assay hallmark. This hallmark confirms that the alloy composition matches the declared purity standard.

The Most Common Gold Purities: 375, 585, 750, and 999

Gold jewelry sold on the Lithuanian market is almost always marked with one of four purity standards: 375, 585, 750, or 999. These cover the full spectrum, from budget-friendly everyday jewelry to investment-grade gold bars, so understanding the differences between them helps buyers make the right purchasing decision.

375 Purity (9K) – A Budget-Friendly Choice

A 375 purity alloy contains 37.5% pure gold, while the remaining 62.5% consists of copper, silver, zinc, or other metals. Due to the relatively low amount of gold, this is the least expensive legally recognized gold purity available on the Lithuanian market.

The higher proportion of alloying metals gives the material additional strength, meaning 9K gold withstands mechanical wear and everyday impacts better than softer, higher-purity alloys. The lower metal cost also makes jewelry more affordable to a wider audience.

However, 375 purity also has disadvantages. Because other metals dominate the alloy, the golden tone appears less rich, while copper and silver in the composition may oxidize over time, causing the jewelry to lose its original shine faster than 585 or 750 purity pieces.

Typically, 9K gold is used to make everyday jewelry, children’s earrings, thin chains, and budget-friendly engagement rings.

585 Purity (14K) – The European Standard for Everyday Wear

A 585 purity alloy contains 58.5% pure gold, while the remaining 41.5% consists of copper, silver, or palladium, depending on the desired color. A copper-rich alloy creates a red or rose tone, silver produces the classic yellow shade, while palladium forms white gold.

This purity has become the European standard because it achieves an optimal balance between four qualities: sufficient purity, mechanical strength, a rich gold color, and an accessible price. Due to the higher proportion of alloying metals compared to 750 purity, 14K gold withstands everyday wear better, allowing jewelry to maintain its shape and shine for longer.

585 purity gold is used to create wedding rings, engagement rings, earrings, bracelets, and chains intended for continuous wear. The strength of this alloy explains why 14K gold dominates the everyday jewelry segment across the EU market.

750 Purity (18K) – A Prestigious Standard

A 750 purity alloy consists of 75% pure gold and 25% other metals such as copper, silver, palladium, or nickel, depending on the desired shade. The higher gold content makes this purity prestigious, and it is most commonly chosen for high-end jewelry pieces.

The main advantage of 750 purity is its richer and deeper golden color, which lower-purity alloys cannot achieve. The likelihood of skin allergies is also reduced because there are fewer alloying metals, especially nickel or copper.

However, the higher gold content also has disadvantages. 18K gold is softer, making it more susceptible to scratches and deformation during everyday use. The price is also significantly higher compared to 585 purity jewelry.

Because of these qualities, 750 purity is most often chosen for gemstone rings, occasion jewelry, and family heirlooms passed down through generations.

999 Purity (24K) – Investment Gold

999 purity means 99.9% pure gold, while the marking 999.9 or .9999 indicates a higher purity level of 99.99%. These numbers are not synonyms: 999, 999.9, .9999, and 99.99% represent different levels of precision that are important when evaluating the quality of investment gold.

This purity is almost never used in jewelry because pure gold is too soft – it deforms easily under pressure and scratches even during everyday wear. For this reason, jewelers choose stronger alloys containing additional metals.

The main use of 999 purity gold is for investment purposes. It is used to produce gold bars, coins (for example, a 1 troy ounce coin weighing 31.1 g), and is held in central bank reserves.

The English term fine gold is a historical expression referring to gold of the highest purity. This is why investment bars are often marked with the inscription “999.9 fine gold.”

Gold Purity Chart: Markings, Karats, and Percentages

A gold purity chart helps quickly connect millesimal markings with karats and the percentage of pure gold. It includes both the purity standards commonly used in Lithuania and less common international standards.

Purity	Karats	Pure Gold %	Typical Use
333	8K	33,3 %	Budget standard in Germany
375	9K	37,5 %	UK standard, budget jewelry
500	12K	50 %	Rarely used
583	14K	58,3 %	Former Soviet standard
585	14K	58,5 %	European standard
750	18K	75 %	Prestigious jewelry
875	21K	87,5 %	Middle Eastern standard
916	22K	91,6 %	Asian market standard
999	24K	99,9 %	Investment gold
999,9	24K	99,99 %	Highest purity bullion

The table becomes practical when purchasing jewelry and evaluating material value by weight. For example, a 10 g ring of 585 purity contains 5.85 g of pure gold, while a 10 g piece of 750 purity contains 7.5 g.

The difference amounts to 1.65 g of pure metal, which means the material value of the jewelry also differs proportionally according to the current market price of gold. Comparing two jewelry pieces based only on weight can therefore be misleading if purity is not taken into account.

It is worth saving this chart as a reference point when buying gold, evaluating inherited jewelry, or comparing offers in different jewelry stores.

Non-Standard Purity Marks: 925, 583, 875, and 333

Alongside the common 375, 585, 750, and 999 markings, there are also purity standards that often confuse buyers. 925, 583, 875, and 333 each have different origins, purposes, and meanings, so it is important to distinguish between them before purchasing.

925 Purity – Is It Actually Gold?

925 purity almost always refers to sterling silver (92.5% pure silver), not gold. In the Lithuanian jewelry market, a 925 mark on gold is practically nonexistent, because such a purity standard is not part of the official gold classification system.

The confusion usually comes from online stores where descriptions such as “925 gold” sometimes appear. In most cases, this refers to gold-plated silver, also known as gold-plated silver or vermeil, where a sterling silver base is coated with a thin layer of gold. The actual metal value is determined by the silver, not by the surface gold plating.

Before purchasing, compare the price with market values: if the amount is closer to the value of silver by weight, it is not a solid gold item. A significant price difference usually reveals the true metal composition.

When buying online, always ask for a photo of the purity hallmark or a certificate confirming the material composition.

Russian Gold 583 Purity

583 purity is a Soviet-era standard that was used until 1994 and corresponds to an alloy containing 58.3% pure gold. After the collapse of the Soviet Union, Russia switched to the international 585 marking, which is why 583 is now considered a historical hallmark.

Compared with the European 585 standard, the practical difference is minimal – only 0.2% less pure gold – but the official marking is different. Jewelry with 583 purity is therefore evaluated separately rather than treated as identical to 585 pieces.

In Lithuania, 583 purity gold is often found in antique shops, pawnshops, and inherited family collections. Such jewelry frequently carries additional collectible or sentimental value beyond the simple worth of the metal by weight, especially if the original Soviet manufacturer’s hallmark or box has survived.

875 and 333 Purity – Where Are They Used?

875 purity corresponds to 87.5% pure gold (21K) and was widely used during the Soviet era as well as in some Eastern countries, including the Middle East and Central Asia. On the Lithuanian market, this purity is rare today and is mostly found in inherited or antique jewelry.

333 purity indicates 33.3% pure gold (8K) and is considered a budget standard in Germany. In Lithuania, it appears only rarely, mainly in older imported jewelry from German-speaking countries.

The minimum legally permitted gold purity within the EU is determined by each country’s national regulations. In Lithuania, the minimum legal purity for gold jewelry is 375, which is why 333 purity items are not officially sold as gold jewelry in the country.

How to Check Whether Gold Purity Is Genuine?

Authenticity verification begins with a visual inspection. On the inside of the jewelry piece, the lower part of a ring, or the clasp of a chain, look for three elements: the purity numbers (for example, 585 or 750), the manufacturer’s mark, and the official state assay hallmark. In Lithuania, this hallmark is marked with the letters CCM together with the purity number, confirming that the item has been tested by the Lithuanian Assay Office.

The magnet test helps identify obvious counterfeits. Pure gold is not magnetic, so a strong neodymium magnet will not attract genuine gold. However, the test is not absolute, because some alloys containing iron or nickel may still react to a magnet even if they contain a portion of gold.

The density test is based on a physical property of gold: pure gold has a density of 19.3 g/cm³. A 585 purity alloy has a density of around 13.5 g/cm³, while 750 purity is approximately 15.5 g/cm³. By weighing the jewelry both dry and submerged in water, the density can be calculated and compared with reference values.

The acid test is a professional method in which nitric acid is applied to a small scratch on the metal surface and the reaction is observed. Home testing kits may damage the surface, so this method is best left to professional jewelers.

The most accurate non-destructive method is XRF (X-ray fluorescence) analysis, commonly used in pawnshops and jewelry workshops. Within seconds, the device reveals the exact composition of the alloy.

In Lithuania, an official certificate is issued by the Lithuanian Assay Office after laboratory testing. It is also important to compare the price with the market value of gold by weight: if an offer is significantly lower than the calculated metal value, this is a clear warning sign of a counterfeit.

Gold Purity: Frequently Asked Questions

Which Gold Purity Is Best for Jewelry?

In Europe, the most popular choice is 585 purity (14K) because it offers the optimal balance between price, durability, and shine. It is the best option for everyday jewelry that is constantly exposed to skin contact, clothing, and moisture.

750 purity (18K) is considered prestigious and has a richer golden tone, but because of its higher pure gold content it is softer, making it more suitable for occasion jewelry worn less frequently. The best purity depends on the intended use: for everyday wear – 585, for investment – 999, and for prestige – 750.

What Does 585 Purity Mean and How Many Karats Is It?

585 purity means that the alloy contains 58.5% pure gold, while the remaining portion consists of copper, silver, or palladium, which give the metal strength and color.

This corresponds to 14 karats, because according to the formula 14K × 1000 / 24 the result is 583.3, which by international agreement is rounded to 585. This purity became the European standard because of its balance between price and durability.

Is 925 Purity Gold?

925 purity almost always refers to sterling silver (92.5% pure silver), not gold. In the classification of precious metals, 925 is not a recognized gold purity standard.

Online, gold-plated silver (vermeil) jewelry is sometimes misleadingly advertised as “925 gold.” Always check the hallmark and the price: if the item’s value is closer to silver than gold, this reveals the true metal composition.

How to Distinguish Real Gold from Fake Gold at Home?

The simplest method is the magnet test, because pure gold is not magnetic and will not be attracted by a strong neodymium magnet. You should also check the purity hallmark on the inside of the jewelry and compare the price with the market value of gold by weight.

The most reliable option is professional testing at the Lithuanian Assay Office or a trusted jewelry store. It is worth avoiding home acid tests even when suspicions are strong, because they may irreversibly damage the surface of the jewelry.

What Is the Difference Between Russian 583 Gold and 585 Gold?

583 is a Soviet-era standard (58.3% pure gold) that was used until 1994, while 585 is the current European standard (58.5%). The practical difference is only 0.2%, so the physical properties of the metal are almost identical.

However, 583 purity jewelry is usually older and in Lithuania is mostly found in antique shops, pawnshops, or inherited collections. Such pieces may carry collectible or sentimental value that exceeds the simple value of the metal by weight.

Understanding gold purity standards makes it easier to recognize a quality piece of jewelry and evaluate its long-term value. If you are looking for jewelry whose authenticity you can trust, it is worth choosing handmade creations from a master jeweler’s workshop, where every gram of metal passes through a careful creative process.

In Pure Idea Jewelry, silver and gold alloys become personal stories, created for the woman who seeks both aesthetics and meaning. We invite you to explore the wedding ring collection, gemstone rings, and delicate earrings and bracelets, all crafted with attention to every detail and precision of purity.