Will Gold Leaf Burn
Real gold leaf (24k yellow gold, in loose-leaf form) may melt, but it retains material presence and color.
“Mimic gold”, an alloy or even colored other metal, discolors through oxidization and distorts based on melting temperature.
“Gold on base”, as a painted-on coloring, burns away to carbonized ashes that tend to float away. “Gold on base”, as transfer leaf (pure gold leaf on backing): the fragile gold leaf is most likely fractured by the burning backing and tends to drop off with pieces of the carbonized backing. The video does not clarify the type of “Gold on base”, painted or transfer.
Gold leaf, an ultra-thin sheet of gold, is prized for its decorative applications in art, architecture, and culinary presentations. Its behavior under heat varies depending on its purity and composition.
Pure Gold Leaf (24k):
Pure gold has a melting point of approximately 1,064°C (1,947°F). When exposed to high temperatures, such as those from a butane torch, pure gold leaf will melt but not burn. It retains its material presence and distinctive color, as gold does not oxidize or discolor upon heating. Therefore, pure gold leaf can withstand significant heat without combusting or losing its characteristic appearance.
Imitation Gold Leaf:
Imitation gold leaf, often referred to as “mimic gold,” is typically composed of alloys like brass (a mixture of copper and zinc) or other metals designed to resemble gold. These metals have lower melting points than pure gold and are prone to oxidation. When subjected to heat, imitation gold leaf is likely to discolor due to oxidation and may distort or melt at lower temperatures compared to pure gold. This results in a loss of luster and a change in appearance, distinguishing it from genuine gold leaf under thermal stress.
Gold Paint and Transfer Leaf:
“Gold on base” can refer to materials like gold paint or transfer leaf. Gold paint consists of metallic particles suspended in a binding medium. When exposed to flame, the binding medium burns away, leaving behind carbonized ashes that may disperse, and the metallic particles may oxidize or lose their sheen. Transfer leaf involves a thin layer of gold (or imitation gold) adhered to a backing paper. Upon heating, the backing material is likely to burn or char, potentially fracturing the delicate gold layer, causing it to detach or deteriorate.
Practical Implications:
Understanding the thermal properties of gold leaf is crucial for its application in various fields. In culinary arts, where gold leaf is used as a garnish, exposure to high heat should be avoided to maintain its aesthetic appeal. In artistic gilding, knowing the heat tolerance of the specific type of gold leaf ensures the longevity and durability of the artwork. For restoration work, distinguishing between pure and imitation gold leaf can inform appropriate conservation techniques, especially when heat treatments are involved.
In summary, pure gold leaf can withstand high temperatures without burning or discoloring, melting only at its high melting point. In contrast, imitation gold leaf and gold-based products are more susceptible to oxidation, discoloration, and structural degradation when exposed to heat. This distinction is essential for professionals and enthusiasts working with gold leaf across various disciplines.
