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
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Questions about the product?

Markus Legeler

+49 7171 607 204

For inquiries and additional information
please contact

Umicore AG & Co. KG
Rodenbacher Chaussee 4
63457 Hanau-Wolfgang

Tel.: +49 (6181) 59 6005
Fax: +49 (6181) 59 2970

The information and statements contained herein are provided free of charge. They are believed to be accurate at the time of publication, but Umicore makes no warranty with respect thereto, including but not limited to any results to be obtained or the infringement of any proprietary rights. Use or application of such information or statements is at the user´s sole discretion, without any liability on the part of Umicore. Nothing herein shall be construed as a license or recommendation for use, which infringes upon any proprietary rights. All sales are subject to Umicore´s General Conditions of Sale and Delivery.