Agarwood is a fragrant dark resinous wood used in incense, perfume, and small carvings. It is formed in the heartwood Agarwood trees when they become infected with a type of mold (Phialophora parasitica). Prior to infection, the heartwood is odourless, relatively light and pale coloured; however, as the infection progresses, the tree produces a dark aromatic resin, called aloes or agar as well as gaharu, jinko, oud, or oodh aguru. In response to the attack, which results in a very dense, dark, resin-embedded heartwood. The resin-embedded wood is valued in East and South Asian cultures for its distinctive fragrance, and thus is used for incense and perfumes.