Sandalwood is one of the most expensive woods in the world: One kilogram of Indian sandalwood can cost $200. Its unique, long-lasting aroma makes it extremely sought after. And when that aroma is distilled into oil, a single kilogram can cost $8,000. Today, sandalwood oil is a coveted ingredient for perfumes, soaps, and incense. So what's so special about sandalwood's aroma? And is that why the wood is so expensive?