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RHODUNA®-Alloy 1 Rhodium-Ruthenium Electrolyte

RHODUNA®-Alloy 1 Rhodium-Ruthenium Electrolyte

The first pure white electrolytic rhodium alloy

RHODUNA®-Alloy is the first alloy electrolyte in the world combining the high-quality metals rhodium and ruthenium. The basic materials of the new coating are truly royal: A mixture of rhodium, one of the world‘s most valuable precious metal, and the platinum group metal ruthenium.

Its white colour is absolutely equivalent to that of a pure rhodium layer. The electrolyte has all the quality characteristics of high-grade rhodium coatings and surpasses them in durability and uniformity. Its good throwing power even permits the plating of parts with complex geometries. It can be directly deposited on nickel, palladium, silver and gold.

At the same time, the „BrightQueen“ is considerably less expensive than pure rhodium layers.

Further information

Electrolyte characteristics

Electrolyte type

Strongly acidic

Metal content

1.6 (0.8 - 1.8) g/l Rh 0.4 (0.2 - 0.5) g/l Ru

pH value

< 1

Operating temperature

45 (40 - 50) °C

Current density range

4.0 (3.0 - 5.0) A/dm²

Plating speed

Approx. 0.2 μm/min at 4.0 A/dm²

Anode material

MMO (type PLATINODE® 187 SO)

Coating characteristics



Alloy composition

75 wt. % Rh, 25 % Ru

Colour of deposit





600 - 900 HV


  • Very light, white and ultra-bright coatings
  • More uniform layer thickness
  • Crack-free up to 1 μm
  • Wide current density range
  • Extremely abrasion-resistant
  • Less expensive than pure rhodium layers
  • Ideal for parts with complex geometries, e.g. chains
  • Suitable for rack and barrel


  • Spectacle frames
  • Writing implements
  • Jewellery
  • Watches


  • Produktblatt_RHODUNA_Alloy_1_EN.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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Our goals for the next Years

Umicore RISE Strategy 2030