E. Alloys

1. Gold

The most precious, valuable and beautiful things are always golden. Is it the glimmer, the warm glow of pure gold? Such fine gold is however very soft. For this reason, other metals, such as silver and copper, are generally added. Niessing prefers gold alloy 750 and higher.

Every piece of gold jewelry bears an engraved number. This designates the share of gold in the alloy by weight, divided into 1000 parts. For example, 750 means that gold makes up 3/4 of the weight. However, its share by volume is significantly less, specifically 58 percent. For this reason, the highest possible share of gold is important for quality. Niessing produces its own alloys in order to maintain optimal quality. Depending on the piece of jewelry, Niessing uses Au 1000 (fine gold), 900, 750 or 585. Au is the chemical symbol for gold (Latin: aurum).

Gold does not have to look golden. Niessing has broadened its color spectrum with special alloys: Yellow, reddish, red, sand gray, gray, green, pale green. Niessing uses no nickel, which can trigger allergies, rather it uses the more expensive and precious metal palladium.

2. IRIS^®

This special alloy of fine silver and fine gold (Au 750) can be recognized based on the gradual shifting of the color from white to yellow. IRIS^® is also a jewelry theme unique to Niessing.

3. Gray gold / white gold

In nature, gold exists only in its unmistakable gold-yellow form. White and gray gold are solely of human manufacture by alloying gold with other metals. In the past, nickel was used for this. Since many people are allergic to nickel, Niessing does not use it at all and makes its alloys with palladium instead. This results in gray gold.

To achieve the typically light color of white gold, rhodium is applied to the finished gray gold ring. The artificial surface created in this way wears off over time. However, it can be reapplied at any time.

4. Platinum

33 times rarer than gold and much more difficult to obtain: platinum enjoys the highest status among the precious metals. It is excellently suited for holding diamonds. Its white color particularly enhances the sparkle of a precious stone.

Platinum is unmistakable, even if its name derives from the Spanish word "platina" (= small silver). Its chemical symbol is Pt. Generally, it is used as Pt 950. This value indicates the level of purity of the alloy. It designates the number of parts of platinum by weight, with the alloy divided into 1000 parts. The remaining 50 parts consist of copper. 950 corresponds to a share by volume of 89 percent platinum. Niessing uses only Pt 950 or Pt 1000 (pure platinum), identifiable in the engraving or hallmark on the piece of jewelry.

The chemical and physical properties of platinum are exceptional. The metal is very tough and extremely malleable. Its melting point of 1772 °C is extremely high. This makes it difficult to work with in the workshop. Platinum retains its original color even after years.
A platinum cube with an edge length of 10 centimeters weights over 20 kilograms. With its high specific weight of 21.45 g/cm3, platinum is clearly heavier than gold. A property that is not visible, but can be felt in a fascinating way. A platinum ring simply feels different than a gold ring. Platinum for everyday wearing? Why not? Platinum is very comfortable even against sensitive skin. Like every ring of precious metal, a platinum ring acquire traces of being worn. Because the material is so strong, a platinum ring retains its weight for a long time.

5. Why does jewelry tarnish?

Jewelry of precious metal tarnishes because its constituents react with the elements in the air. In particular with oxygen and sulfur compounds. Silver jewelry can tarnish black simply from contact with the skin.

If this happens, you can send your jewelry to our workshop or the nearest Niessing store, where we will inspect and clean in professionally.