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What alternatives are available to pure gold in the electroplating process?

January 2026 |

Chemicals

What alternatives are available to pure gold in the electroplating process?

A technical comparison of gold alloy baths versus 23.5 carat gold

Aurega® blend Cu 114 CX and Aurega® blend Cu 118 CX
vs. 23,5-Carat-goldbath: Aurega® pure 218

The electroplating of gold layers plays a central role in decorative applications, in the jewellery industry and in spectacle frames. In view of rising raw material prices and the desire for more robust surfaces, classic 23-carat gold baths are coming under increasing pressure. In this context, alternatives to pure gold are becoming increasingly important.

Aurega® blend Cu 114 CX and Aurega® blend Cu 118 CX are two modern cyanide electrolytes that, thanks to their gold-copper-indium alloys, not only drastically reduce gold consumption but are also technically superior.

1. Gold-copper alloys instead of pure gold

Gold-copper-indium alloy:caratgold content
Aurega® blend Cu 114 CX13 -15 ctapprox. 54 – 62,5 %
Aurega® blend Cu 118 CX15 -18 ctapprox. 62,5 – 75 %
23,5 ct. gold:caratgold content
Aurega® pure 21823,5 ctapprox. 97 %

Aurega® blend baths lead to substantial material and process cost savings, especially with thicker layers (up to 10 µm), without compromising on high-quality appearance.
See cost comparison:

Kostenvergleich reines Goldbad zu Gold-Kupfer Legierungsbäder

Cost comparison of the two gold alloy baths Aurega® blend Cu 114 CX and Aurega® blend Cu 118 CX with the 23.5 carat gold bath, e.g. Aurega® pure 218

Gold price: €142.69/g (as of 26 January 2026)

Costs for 1µm/dm2

  • Aurega® pure 218: 26,13 €
  • Aurega® blend Cu 118 CX: 15,95 €
  • Aurega® blend Cu 114 CX: 11,17 €

2. Stable, reproducible gold colour comparable to 23-carat gold

  • Aurega® blend Cu 118 CX: warm, slightly rosé, 2N
  • Aurega® blend Cu 114 CX: light rosé, 2N

Unlike alternative gold alloys such as Au-Ag alloy baths, layers from gold-copper alloy baths impress with their non-tarnishing properties, lack of green discolouration and permanently stable colour.

3. Increased surface hardness and longer service life compared to 23-carat gold

  • Aurega® blend Cu 114 CX & 118 CX: approx. 400 HV20
  • Aurega® pure 218: approx. 220–230 HV20

The harder layers are more scratch-resistant, abrasion-resistant and ideal for jewellery and spectacle frames that are subject to daily wear and tear.

4. Safety and environmental advantages in comparison: Aurega® pure 218 versus gold-copper alloys

  • Aurega® pure 218: no free cyanide
  • Aurega® blend Cu 118 CX: ca. 33 g/l free cyanide
  • Aurega® blend Cu 114 CX: ca. 25 g/l free cyanide

Although the 23.5 ct gold bath Aurega® pure 218 offers further advantages in terms of safety and wastewater treatment, both gold-copper alloys are also considered to be safe and environmentally friendly.

5. High technical quality in gold-copper alloys and pure gold coatings

  • shiny, ductile layers
  • resistant to CuCl₂ and polysulphides
  • ideal for jewellery, decoration and optical frames

Overview

Aurega® blend Cu 114 CX

Gold content:
13 ct – 15 ct
58,5 %
(depending on the applied current density)

Colour:

  • 2N
  • warm, slightly roségold tone
  • L* 90,5
    a 4,0
    b 18,0
  • Stable over time thanks to copper & indium
  • No tarnishing

Thickness:
up to 10 µm

Layer:
bright layer, ductile and slightly levelling

Hardness & durability:

  • hard
  • 400 HV20
  • Durability without toxic additives
  • scratch- and abrasion resistant

Chemical resistance:

CuCl2 and polysulfide resistant

Environmental sustainability

  • Contains Indium
  • Contains approx. 25 g/l potassium cyanide
  • Safer in application
  • Easier waste management
About the product

Aurega® blend Cu 118 CX

Gold content:
15 ct – 18 ct
75 %
(depending on the applied current density)

Colour:

  • 2N
  • warm, slightly roségold tone
  • L* 86,3
    a 5,1
    b 28,0
  • Stable over time thanks to copper & indium
  • No tarnishing

Thickness:
up to 10 µm

Layer:
bright layer, ductile and slightly levelling

Hardness & durability:

  • hard
  • 400 HV20
  • Durability without toxic additives
  • scratch- and abrasion resistant

Chemical resistance:

CuCl2 and polysulfide resistant

Environmental sustainability

  • Contains Indium
  • Contains approx. 33 g/l potassium cyanide
  • Safer in application
  • Easier waste management
About the product

Aurega® pure
218

Gold content:
23,5 ct
97 %

Colour:

  • 2N
  • warm, slightly roségold tone
  • L* 86,3
    a 5,1
    b 28,0



Thickness:
up to 3 µm

Layer:
bright layer, ductile and slightly levelling

Hardness & durability:

  • soft
  • 220 – 230 HV20
  • Mechanically unstable for demanding use cases

Chemical resistance:

CuCl2 and polysulfide resistant

Environmental sustainability

  • Contains Indium and Iron
  • No free Cyanide
  • Even safer in application
  • Even more easily waste management
About the product

Conclusion

Aurega® blend Cu 114 CX and 118 CX enable high-quality, durable and colour-stable gold coatings in pale gold and rose gold. They are harder than conventional 23-carat gold baths and also significantly reduce gold costs.

Aurega® pure 218, on the other hand, impresses with its absence of free cyanide and excellent environmental compatibility.
Reduce costs, increase quality. With our Aurega® product range, the choice is yours.

Reduce costs, increase quality. With our Aurega® product range, the choice is yours.

Contact us now: we will be pleased to send you free samples.

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