Sandalwood is a class of woods from trees in the genus Santalum. The woods are heavy, yellow, and fine-grained, and unlike many other aromatic woods, they retain their fragrance for decades. It is second most expensive wood in the world.
Sandalwood has a distinctive soft, warm, smooth, creamy, and milky precious-wood scent. It imparts a long-lasting, woody base to perfumes from the oriental, woody, fougère, and chypre families, as well as a fixative to floral and citrus fragrances. When used in smaller proportions in a perfume, it acts as a fixative, enhancing the longevity of other, more volatile, materials in the composite. Sandalwood is also a key ingredient in the "floriental" (floral-ambery).