18 carat gold is made by combining pure gold with other metals, specifically consisting of 75% gold parts and 25% alloys. This mixture achieves the desired purity level defined by the karat system.
Understanding Gold Karats
The term "karat" is a measure used to indicate the purity of gold. Think of gold as being divided into 24 parts.
- 24 Karat Gold: Represents gold that is 100% pure.
- 18 Karat Gold: As the reference states, this is made of 75% gold parts and 25% alloys.
This means that for every 24 total parts of metal, 18 parts are pure gold, and 6 parts are other metals.
The Role of Alloys
The remaining 25% in 18 carat gold is made up of alloys. These are other metals added to the pure gold. The reference mentions that these alloys can be a range of other metals, including silver, copper, and nickel.
Adding alloys serves several important purposes:
- Durability: Pure gold (24k) is very soft and easily scratched or bent, making it impractical for everyday use in jewelry. Alloys increase its strength and hardness.
- Color: By varying the type and proportion of alloys, different colors of gold can be created, such as:
- Yellow Gold: Typically uses silver and copper alloys.
- White Gold: Often uses nickel, palladium, or silver alloys (though nickel is less common now due to allergies).
- Rose Gold: Uses a higher proportion of copper alloy.
- Cost: Alloys are less expensive than pure gold, making 18k gold more affordable than 24k gold, while still retaining a high gold content.
Composition Breakdown
Here's a simple breakdown of 18 carat gold composition:
| Component | Percentage | Karat Parts (out of 24) |
|---|---|---|
| Pure Gold | 75% | 18 |
| Alloys | 25% | 6 |
| Total | 100% | 24 |
The exact metals used in the alloy mixture can vary depending on the desired properties (like color and hardness) and the manufacturer. Common alloys include:
- Silver
- Copper
- Nickel (less common in some regions like the EU)
- Zinc
- Palladium (often used in white gold)
In essence, making 18 carat gold is a metallurgical process of carefully mixing 75 parts of pure gold with 25 parts of a selected blend of other metals in a molten state, which is then solidified and processed into usable forms like ingots, wires, or sheets.
