Choosing the right gold plating solution is a critical factor that determines not only the durability and aesthetics of the coating but also the safety for users. For jewelry items such as rings, bracelets, necklaces, or watches — pieces that are in direct contact with the skin — there is a risk of irritation if the plating contains harmful metals. A highly effective solution in this case is AURUNA® 215 Pale – an alloy gold plating solution that stands out with its elegant pale gold tone, skin safety, and ease of use in production. Let’s explore the Auruna 215 Pale gold plating solution with PMAC in the following article.
1. Auruna 215 – A Premium Gold Plating Solution from Europe
Auruna® 215 Pale by Umicore (Germany) is a hard gold electroplating solution with a distinctive pale gold color, specifically designed for decorative applications such as jewelry, watches, and high-end metal accessories. What sets Auruna 215 apart is its ability to produce a beautiful, uniform, and skin-safe coating, thanks to the absence of nickel and cobalt – two common allergenic metals.
With a formulation containing gold, iron, and indium, Auruna 215 ensures excellent adhesion, consistent coloration, and outstanding hardness, enhancing scratch resistance during use.
2. Outstanding Advantages of Auruna 215 Gold Plating Solution
2.1 Nickel- and Cobalt-Free Composition
Nickel and cobalt are among the most common causes of skin irritation, rashes, and even contact dermatitis in jewelry wearers. By completely eliminating these metals, Auruna 215 enhances safety and meets export standards for strict markets such as the EU, Japan, and the United States.
2.2 Elegant, Uniform Pale Gold Tone
Auruna 215 delivers a soft, refined pale gold finish that is highly favored in modern jewelry design. Thanks to its indium content, the coating maintains uniform color throughout the production process, minimizing blotches or discoloration over time.
2.3 High Hardness and Scratch Resistance
With a hardness rating of approximately 220 HV, the Auruna 215 coating not only provides visual appeal but also superior scratch resistance, enhancing product longevity and durability in real-world usage.
2.4 High Gold Purity (~96%)
The coating contains about 96% pure gold, equivalent to approximately 23 karats, ensuring high gloss, full coverage, and premium aesthetic – key qualities in high-end jewelry.
2.5 Flexible Operation – Suitable for Various Plating Technologies
With a mildly acidic profile, the solution is compatible with both rack plating and barrel plating. This allows easy implementation in both small-scale and industrial production without the need for extensive equipment changes.
3. Auruna 215 Technical Specifications
| Parameter | Standard Value |
| Solution Type | Mildly acidic |
| Gold Content | 1.5 g/l (1.3 – 1.7 g/l) |
| Iron (Fe) Content | 0.5 g/l (0.4 – 0.6 g/l) |
| Indium (In) Content | 1.0 g/l (0.8 – 1.2 g/l) |
| pH Level | 4.0 (3.8 – 4.5) |
| Operating Temperature | 45°C (40 – 50°C) |
| Current Density | 2.5 A/dm² (2.0 – 3.0 A/dm²) |
| Gold Deposition Rate | ~0.11 µm/min |
| Gold Deposition Yield | ~7.8 mg/A·min |
4. Coating Characteristics from Auruna 215
The coating formed using Auruna 215 is not only visually appealing but also of high quality due to its key properties:
- Color: Pale gold (1N), bright and uniform
- Gold Purity: Approximately 96%
- Iron Content: ~3.5%
- Indium Content: ~0.5%
- Hardness: ~220 HV (providing excellent scratch resistance)
- Gold Karat Value: ~23K
- Coating Density: ~17.5 g/cm³
This coating is ideal for jewelry and accessories that come into direct contact with the skin, offering hypoallergenic properties and long-lasting color stability.
5. Auruna 215 Plating Solution Preparation Guide
5.1 Required Materials:
- 500 ml Auruna 215 Initial Concentrate (without gold)
- 2.2 g Potassium Gold Cyanide (68.2%) – containing approximately 1.5 g of pure gold
- Deionized Water
- Citric Acid or Pure KOH for pH adjustment
5.2 Procedure to Prepare 1 Liter of Plating Solution:
- Pour 500 ml of Auruna Initial into the tank.
- Add deionized water to reach approximately 800 ml.
- Dissolve 2.2 g of potassium gold cyanide (68.2%) in deionized water, then add to the solution.
- Add more deionized water to reach a total volume of 1000 ml.
- Adjust the pH to 4.0 using citric acid or KOH solution.
5.3 Recommended Operating Conditions:
- Solution Density: ~1.050 g/cm³
- Minimum Agitation: 5 cm/second
- Agitation and Filtration: Recommended to avoid precipitation and ensure homogeneity
- Operating Temperature: Maintain at 45°C
- Current Density: 2.5 A/dm²
By maintaining these ideal conditions, the resulting gold layer will have excellent adhesion, consistent color, and optimal performance in both aesthetics and quality.
Auruna® 215 Pale is a premium gold plating solution developed with a focus on user health safety, long-lasting color stability, and adaptability to diverse production processes. With its elegant pale gold layer, hypoallergenic formulation, and gold purity reaching up to 96%, this product fully complies with international standards for high-end jewelry.
If you are seeking a gold plating solution for premium products — where high demands are placed on aesthetics, durability, and skin safety — Auruna 215 is undoubtedly the ideal choice you shouldn’t overlook.