Au750 vs 24K Gold: What’s the Difference & Which to Choose?

Side by side comparison of 24K, 22K, and 18K gold bars showing different hues and purity levels

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When shopping for gold jewelry, you’ll often come across terms like Au750 or 24K stamped on the piece. These numbers reflect the purity and composition of the gold—but what do they really mean? And how do you choose the right one for your needs?

In this guide, we'll break down everything you need to know about Au750 gold (also known as 18K gold) vs 24K gold—from purity levels and hallmark stamps to color, durability, and investment value.

What Does Au750 Mean?

Au750 is a purity mark that indicates the jewelry is made of 75% pure gold, with the remaining 25% being alloy metals such as copper, silver, or palladium.

  • Au” is the chemical symbol for gold (from the Latin word Aurum)

  • 750” means 750 parts per thousand are pure gold

  • Au750 is equivalent to 18 karat gold

This blend gives the gold better strength, more color variety, and makes it suitable for daily wear jewelry like rings, bracelets, and necklaces.

Close up of ring interior engraved with Au750 hallmark indicating 18K gold

What Is 24K Gold?

24K gold is pure gold, or nearly 99.9% gold content. It is the highest level of gold purity commercially available.

  • Hallmark stamps include “24K”, “999”, or “Au999”

  • It has a rich, deep yellow color

  • Very soft and malleable, making it prone to scratches or bending

Because of its softness, 24K gold is rarely used for jewelry that’s worn daily. It is more common in gold bars, coins, and investment-grade products.

Macro view of 24K stamp on a pure gold coin

Au750 vs 24K Gold – Side-by-Side Comparison

Feature

Au750 (18K Gold)

24K Gold

Purity

75% gold + 25% alloy 

99.9% pure gold

Hallmarks

Au750, 750, 18K

24K, 999, Au999

Color

Yellow, rose, white (depends on alloy)

Deep yellow

Durability

Strong, suitable for daily wear

Soft, prone to dents and bends

Hypoallergenic? 

Often, unless alloy contains nickel

Yes

Price

More affordable than 24K

Most expensive per gram

Best for

Fashion jewelry, wedding rings

Collectibles, investment, heirlooms

Color Variants of Au750 (18K Gold)

One advantage of 18K gold is its ability to be alloyed into various colors:

  • Yellow gold: classic blend with silver and copper

  • White gold: blended with palladium or nickel; often rhodium-plated

  • Rose gold: rich pink hue from higher copper content

  • Green gold (less common): includes silver and cadmium

This makes Au750 a versatile choice for custom jewelry and modern trends.

Three 18K gold rings in yellow, rose, and white variants showing alloy color differences

Which Is Better: Au750 or 24K?

It depends on your purpose:

✔ Choose Au750 if you want:

  • Durable, daily-wear jewelry

  • Stylish color options (rose, white, yellow)

  • A balance of luxury and practicality

✔ Choose 24K if you want:

  • Maximum gold purity

  • A long-term investment or family heirloom

  • Traditional pieces with cultural significance (common in Asia & the Middle East)

Hallmark Guide: How to Identify Au750 and 24K Gold

Look for stamped hallmarks on the inner side of rings or clasps on chains:

  • Au750 / 750 / 18K = 75% gold

  • Au999 / 999 / 24K = 99.9% gold

Make sure these are accompanied by reputable jeweler marks or verified certificates.

To ensure genuine purity, you can also use scientific tools like the Karatmeter (X‑Ray gold purity tester)—a fast, non‑destructive method commonly used by jewelers and assay labs.

Jewelry Care Tips

Au750 Gold:

  • Clean with mild soap and water

  • Avoid harsh chemicals (perfume, chlorine)

  • Polish every 6–12 months

24K Gold:

  • Store in separate soft pouches to avoid scratching

  • Rarely polish—handle with care due to softness

Cleaning gold jewelry with a soft cloth to maintain shine and durability

FAQ: Au750 & 24K Gold

What does Au750 mean?

Au750 means 75% gold purity, also called 18K gold.

Is Au750 real gold?

Yes. It is real gold, mixed with alloy metals for strength and color variation.

Is Au750 better than 24K?

Not better or worse—just different. Au750 is stronger for daily wear; 24K is purer but softer.

Does Au750 gold tarnish?

Rarely. It may dull slightly over time, especially white or rose gold, but doesn’t rust or corrode.

Can I wear Au750 if I have sensitive skin?

Yes, especially if it’s nickel-free. Look for hypoallergenic alloys or rhodium-plated options.

Conclusion: Which Should You Choose?

If you're buying jewelry to wear and enjoy, Au750 is the gold standard—strong, stylish, and valuable. If you're buying gold for investment or traditional gifting, 24K gold is unmatched in purity.

Ultimately, the best choice depends on your lifestyle, taste, and purpose.

Jeweler presenting a custom gold ring to a client, highlighting personalized gold jewelry service

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