Agarwood does not have one single smell. Its aroma can be subtle and woody in its natural state, then become much richer and more complex when the resin is gently heated.
Before heating, agarwood can have a quiet aroma that is difficult to describe with just one word. Depending on the material, you may notice woody, earthy, slightly sweet, or resinous impressions.
This is why simply holding a piece of agarwood to your nose may reveal only part of its character. The intensity and balance of the aroma can vary from one piece to another.
When agarwood is heated, aromatic compounds are released more readily. The fragrance can become deeper, warmer, sweeter, more resinous, or smoky, depending on the material and how it is heated.
People may describe these impressions as honeyed sweetness, floral sweetness, orchid-like, creamy or milky, cooling, nutty, woody, earthy, spicy, or smoky. These descriptions are sensory vocabulary, not rigid categories, and one piece may express several of them at different moments.
The aroma can also change with the tree, the growing environment, resin development, the material itself, and the way it is experienced. Two pieces that look similar may therefore smell quite different.