Material Guide

Metal Guide

Metal Guide

"Is this material right for me?" "What is the difference between K18 and K10?"
For those with such questions. About the metal that supports the brilliance of jewelry,
we offer a clear guide, easy to follow even for first timers.

There is no single "correct" material. What matters is choosing the one that suits your lifestyle and taste. Pt950 and K18 are lovely for bridal pieces, K10 for everyday wear, and SV925 for those who enjoy the beauty of aging.

01

What is Karat?

Understanding Purity (Karat)

The "K" in gold stands for Karat. Based on pure gold (K24), it indicates the proportion of gold contained. The higher the number, the more gold; the lower, the more of other metals (alloys) are mixed in.

K24Pure gold 99.9% K18Gold 75% K14Gold 58.5% K10Gold 41.7% PLATINUM Pt950Platinum 95% Pt900Platinum 90% SILVER SV925Silver 92.5%
02

Metal Comparison

Metal Comparison

PurityColourTarnishPrice rangeAD
K2499.9%Deep goldNone$$$$$
K1875%Rich goldResistant$$$$●
K1041.7%Pale goldRarely$$●
Pt95095%Silver whiteNone$$$$●
Pt90090%Silver whiteNone$$$●
SV92592.5%SilverAges over time$●

AD = materials offered at ANNA DIAMOND

03

Gold Color Variations

Differences in Gold Color

The color of gold jewelry changes with the type of alloy mixed in. Even the same K18 can take on entirely different expressions depending on the blend.

Yellow GoldGold 75% + Silver 12.5% + Copper 12.5% Pink GoldGold 75% + Copper 20% + Silver 5% White GoldGold 75% + Palladium 25%
04

Platinum vs White Gold

The Difference Between Platinum and White Gold

They are often confused because they look alike, but they are entirely different metals.

05

Which Metal for You?

Recommendations by occasion

Engagement and Wedding Rings

Pt950Pt900K18

Jewelry to Wear Every Day

Pt950K18K10

Your First Piece of Jewelry

K10SV925

Concerned About Metal Allergies

Pt950Pt900K18
06

Hallmarks

Reading the Hallmark

Inside each piece of jewelry, a hallmark indicating the material is engraved.

HallmarkValueMaterialMeaning
K24999Pure goldGold 99.9%
K1875018K goldGold 75%
K1041610K goldGold 41.7%
Pt950950PlatinumPlatinum 95%
Pt900900PlatinumPlatinum 90%
SV925925SilverSilver 92.5%
07

Why Hardness Differs

Why Hardness Differs

Pure gold (K24) is a very soft metal. Mixing in alloys (silver, copper, palladium and so on) makes the crystal structure more complex and increases hardness. K10 has a higher alloy ratio than K18, so it is harder, but its gold color and tarnish resistance are more subdued.

Pt950 and Pt900 also achieve ample hardness for bridal rings with just a small amount of alloy. Choosing a material is not about "the harder the better" but about balancing beauty, durability, and gentleness on the skin.

Soft ←　　　　　　　　　　　　　　　　→ Hard K24Pure gold K1875% K1041.7%Higher alloy ratio = harder Pt95095% Pt90090% SV92592.5% * This is a general guide to hardness. Actual hardness varies with the alloy blend.
08

Where Metals Come From

Where Precious Metals Are Sourced

If you care about materials, it is worth knowing where the precious metals come from.

Gold China / Australia / Russia / Canada Annual production about 3,000 tons Platinum South Africa (about 70% of the world) Annual production about 180 tons Silver Mexico / Peru / China Used in adornment since ancient times
09

Hallmarks

Reading the Hallmark

Inside each piece of jewelry, a hallmark indicating the material is engraved. When you hold a piece in your hands at the store, do take a look.

HallmarkNumeric NotationMaterialMeaning
K24999Pure goldGold content 99.9%
K1875018K goldGold content 75%
K1458514K goldGold content 58.5%
K1041610K goldGold content 41.7%
Pt950950PlatinumPlatinum content 95%
Pt900900PlatinumPlatinum content 90%
SV925925Sterling silverSilver content 92.5%

Every ANNA DIAMOND piece carries a hallmark for both material and brand.

10

FAQ

Frequently Asked Questions

K18 has a beautiful color and is ideal for bridal and special jewelry. K10 is harder and more affordable, well suited to everyday jewelry. We recommend K18 for a special piece and K10 for something to enjoy casually.
Platinum is a naturally white metal that does not tarnish or lose its plating. White gold is gold based with rhodium plating, which can fade over time. For a lifelong piece, we recommend platinum.
We recommend Pt950, Pt900, and K18. Platinum in particular is a material that rarely triggers allergies. ANNA DIAMOND uses nickel free alloys, so you can wear K18 with confidence as well. If you are concerned, we recommend a patch test beforehand.
Plating is a surface coating that wears away with use. ANNA DIAMOND does not use any plated products. We craft everything only with solid, high grade materials such as K18, K10, Pt950, Pt900, and SV925. This delivers the true brilliance and durability of the metal itself, which plating cannot achieve.
"K18" and "750" indicate 18K gold, "K10" and "416" indicate 10K gold, "Pt950" indicates platinum 950, and "925" indicates sterling silver. Every ANNA DIAMOND piece carries a hallmark for both material and brand.