Alloy Identification

Alloy Name: 18ct Yellow Gold

Alloy Type: Yellow Gold

Gold Purity: 75.0%

Karat Rating: 18 Karat (18ct)

Appearance: Warm yellow metal, traditional choice for fine jewelry.

Elemental Composition (by weight)

Note: Copper and silver are used to create the warm yellow color and improve hardness.
Exact proportions of the base metals have been omitted to protect the proprietary alloy.

Physical Characteristics

• Color: Rich yellow
• Density: ~15.6–16.0 g/cm³
• Melting Range: 1,040–1,070°C
• Hardness (Vickers): ~120–140 HV (annealed)
• Workability: Excellent for casting, soldering, and fabrication
• Tarnish Resistance: Moderate; may darken slightly over time

Applications

This alloy is typically used in:

• Classic yellow gold jewelry (rings, earrings, pendants)
• Wedding bands and heritage pieces
• Jewelry requiring warm color and traditional appearance

Conclusion

This 18ct yellow gold alloy meets standard specifications with 75% fine gold and 25% copper and silver base metals. The composition ensures the desirable rich yellow color combined with adequate mechanical strength for durable jewelry pieces.