Rosewood oil is steam distilled from the wood of the tree. This tree grows in Brazil and is mostly used commercially for the wood! It is unique oil that can be hard to find in therapeutic quality. The flavoring industry and some of cosmetic companies were the biggest users of rosewood until they switched to synthetics. The trees were harvested in large numbers from the 1930s through the 80s to be distilled into the essential oil that also came to be sold in the natural products industry.