Basins (and bathtubs) made from wood sound improbable, but they are becoming quite fashionable nowadays thanks to the unique, warm look that timber grain provides. These types of sinks are often made using woods like teak or huon pine. Timber basins are typically made from many pieces of wood laminated together and then coated using techniques drawn from disciplines like boat building.
The wood is normally treated with a paint or varnish first to prevent degradation due to UV light, and then very generously coated in an protective epoxy to ensure that the wood is completely protected from the water. The result is a beautiful, stylish wooden sink.
While these sorts of sinks are normally custom built by an artisan, they're now also being offered by some larger commercial kitchen and bathroom brands. Regular maintenance and care is vital for timber sinks - if the water manages to penetrate the coatings, it will make short work of the timber.