Gold, platinum, and silver are three important minerals that potters and ceramic artists should be familiar with. In addition to creating beautiful colors and effects, they also add luxury, distinctiveness, and value to ceramic pieces.
These three minerals can be used for overglaze ceramic decoration or as components with other substances to create a variety of shades and effects. Each has different properties and uses. Let's get to know gold, platinum, and silver in ceramics.
Gold (Au) Mineral
Gold can be used to decorate glazed ceramic ware, commonly in the form of Gold Luster for luxurious decoration, such as Benjarong ware. Additionally, gold can be used as a substance to create purple, magenta, pink, and ruby red colors.
Historical records indicate that the use of gold to decorate ceramic products first occurred at the Meissen factory in Germany in 1830. Twenty-one years later, France patented the liquid gold luster mixture.
For glossy gold luster, gold makes up approximately 12% of the composition, dissolved in a resin solution. Various products are available, including glossy and matte types, suitable for decorating ceramic surfaces to enhance beauty and luxury.
Platinum (Pt) Mineral
Platinum is commonly used for writing and decorating on glazed ceramic ware because it is a stable metal and highly resistant to oxidation. This makes it suitable for ceramic decoration requiring brilliance and color durability.
Furthermore, potters can use palladium mixed with platinum to create a more brilliant silver effect, helping to stabilize the silver color for longer.
Platinum can also be used to create gray tones in ceramic glazes, but this is less common due to its high cost. Potters often choose other, more cost-effective raw materials for preparing gray glazes.
Silver (Ag) Mineral
Silver has a distinctive property of readily reacting with oxygen, causing changes in color and effects on ceramic surfaces. Silver Oxide can produce yellow in low-temperature glazes without limestone and zinc, but with the presence of limestone and zinc, the color may shift to brown.
In some cases, if silver oxide is applied to a glazed surface and the piece is fired in a reduction atmosphere, it can create a luster effect on the glazed surface.
Creating a Luster Effect on Ceramics
Historically, preparing yellow luster colors might involve firing in a strong reduction atmosphere at approximately 300–700 °C. After firing, the surface might need to be polished to create a luster on an opaque white glaze.
For creating luster colors in contemporary ceramics, various compounds can be used, such as lead borate, bismuth oxide, and silver compounds like silver chloride or silver carbonate in a resin solution. These are then fired at approximately 650–700 °C in an oxidation atmosphere to create a luster effect on the ceramic surface.
However, when choosing precious metal compounds and firing to create effects on ceramics, it is crucial to carefully study the properties of the raw materials and the manufacturer's recommendations, as temperature, firing atmosphere, and glaze composition all affect the resulting color and effect.
Gold, platinum, and silver thus play a role not just in creating beautiful colors, but also as important elements that add dimension, brilliance, and luxury to ceramic works. When chosen appropriately for the glaze type, decoration technique, and firing temperature, they can create unique and valuable pieces.