Gold leaf is gold that has been hammered into thin sheets by goldbeating and is often used for gilding. Gold leaf is available in a wide variety of karats and shades. The most commonly used gold is 22-karat yellow gold.Gold leaf is a type of metal leaf, but the term is rarely used when referring to gold leaf. The term metal leaf is normally used for thin sheets of metal of any color that do not contain any real gold. Pure gold is 24 karats. Real yellow gold leaf is about 91.7% pure gold. Silver colored white gold is approximately 50% pure gold.Layering gold leaf over a surface is called gold leafing or gilding. Traditional water gilding is the most difficult and highly regarded form of gold leafing. It has remained virtually unchanged for hundreds of years and is still done by hand.

A leaf is an organ of a vascular plant and is the principal lateral appendage of the stem.The leaves and stem together form the shoot. Leaves are collectively referred to as foliage, as in "autumn foliage."
Diagram of a simple leaf.
Apex Midvein (Primary vein) Secondary vein. Lamina. Leaf margin Petiole Bud Stem
Although leaves can be seen in many different textures and sizes, typically a leaf is a thin, dorsiventrally flattened organ, borne above ground and specialized for photosynthesis. In most leaves, the primary photosynthetic tissue, the palisade mesophyll, is located on the upper side of the blade or lamina of the leaf  but in some species, including the mature foliage of Eucalyptus, palisade mesophyll is present on both sides and the leaves are said to be isobilateral. Most leaves have distinctive upper (adaxial) and lower (abaxial) surfaces that differ in colour, hairiness, the number of stomata (pores that intake and output gases), epicuticular wax amount and structure and other features.

A leaf is an organ of a vascular plant and is the principal lateral appendage of the stem. The leaves and stem together form the shoot. Leaves are collectively referred to as foliage, as in "autumn foliage."