AURUNA® 5500 EF Gold Electrolyte for Electroforming

Arsenic-free electrolyte for fine gold hollow jewellery

AURUNA® 5500 EF is particularly suitable for electroforming. The electrolyte is free of arsenic and produces hard, semi-bright, thick gold layers. It is mainly used to produce high quality hollow jewellery with layers between 150 and 200 micrometer. Mandrels may be either made of wax or metal. The excellent hardness up to 180 HV and more than 99.9 percent fineness ensure customer satisfaction, because the hollow jewellery offers outstanding stability in use. It can be polished easily, has good surface quality and convinces with its solder properties. AURUNA® 5500 EF is also ideal when thick fine gold layers are deposited on (non-) precious metals. Creative combinations allow completely new designs.

Electrolyte characteristics

Electrolyte type


Metal content

16 (12 - 20) g/l Au

pH value

5.5 (5.0 - 6.0)

Operating temperature

40 (35 - 45) °C

Current density range

0.5 A/dm²

Plating speed

Approx. 0.3 μm/min at 0.5 A/dm²

Deposition rate

Approx. 110 mg/Amin

Anode material


Current efficiency

Approx. 90 %

Coating characteristics


Fine gold


24 carats


99.9 wt. % Au

Colour of deposit





Approx. 180 HV

Max. coating thickness

Several 100 μm

Density of the coating

Approx. 19.0 g/cm³


  • 24 ct fine gold electrolyte for electroforming
  • Suitable for wax and metal mandrels
  • Layer thicknesses between 150 and 200 micrometer
  • High hardness up to 180 HV at 99.9 percent fineness


  • Electroforming
  • Hollow jewellery
  • Noble jewellery
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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.