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AURUNA® 215 Gold Iron Indium Electrolyte

AURUNA® 215 Gold Iron Indium Electrolyte

Gold alloy electrolyte free of nickel and cobalt

AURUNA® 215 is a colour gold alloy electrolyte for decorative applications, preferably for parts coming into contact with the skin such as jewellery and watches. The essential advantage of the coatings is their freedom from nickel and cobalt, excluding skin allergies caused by these metals.

The weakly acidic gold electrolyte is easy to operate and suitable for rack and barrel, it works very colour-constant. Across a wide operating range, the coating colour (1N - 2N) is independent of pH-value and current density. By adding indium, a uniform colour is achieved.

Electrolyte characteristics

Electrolyte type

Weakly acidic

Metal content

2.5 (2.0 - 3.0) g/l Au 0.5 (0.4 - 0.6) g/l Fe 1.0 (0.8 - 1.2) g/l In

pH value

4.0 (3.8 - 4.5)

Operating temperature

35 (30 - 35) °C

Current density range

1.5 (0.5 - 2.0) A/dm²

Plating speed

Approx. 0.14 μm/ min at 1.5 A/dm²

Anode material

Pt-Ti, MMO (type PLATINODE® 147)

Coating characteristics



Alloy composition

98.5 weight % Au 1.4 weight % Fe 0.05 weight % In

Colour of deposit

Approx. 1N - 2N




220 HV

Max. coating thickness

3 μm

Density of the coating

Approx. 17.5 g/cm³


  • Weakly acidic colour gold electrolyte
  • Pale to light yellow coatings
  • Colour-constant across a wide operating range
  • Uniform colour
  • For decorative applications
  • Non-allergenic since free of nickel and cobalt
  • The coatings are RoHS compliant
  • Suitable for rack and barrel


  • Jewellery
  • Watches
  • Spectacle frames
  • Writing implements
  • Accessories


  • Produktblatt-auruna-215-en-screen-20190416.pdf

Your contact person

Markus Legeler

Markus Legeler

Manager Sales International
T: +49 7171 607 204
F: +49 7171 607 316

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Umicore RISE Strategy 2030