Everything in agarwood comes down to resination. The richer the resin, the deeper the scent and the greater the density. Wood that sinks in water is top grade; half-sinking comes next; floating pieces are entry level.
To authenticate, first study whether the resin veins flow naturally, then warm the wood slightly with body heat and smell it — true agarwood is cool, penetrating and layered, while chemical imitations smell flat and sharp.
Beginners do well to start with small sinking-grade pieces and progress step by step. Never chase the "sinking" label while ignoring the scent itself.
