Most musicians think of Koa as a beautiful and premium tone wood used in all kinds of instruments, but especially acoustic guitars and ukuleles. It is famous for its rich colors and intense three dimensional luminescence with chatoyant figure.
What exactly do you know about this incredible wood? You probably know that it is only found in Hawaii. Koa is completely endemic to Hawaii, once abundant throughout Islands. Koa is the first tree to grow from the Hawaiian lava, live trees cannot be cut on state land, collection on state land can only come from standing dead trees or trees that fall naturally.
Koa is a type of acacia wood. Another famous accacia wood that also can be great tone wood is Tasmanian Blackwood. The image to the right is a example of a extremely fine cut of Tasmanian Blackwood. This wood is cheaper than the highly prized Koa and the finer quality cuts can look almost just like Koa.
The most compelling quality of Koa as a tone wood is the midrange focus with extra top-end brightness and chime. The more a Koa guitar is played, the more the tone opens up to a richer, sweeter, more resonant tone.
Koa is prized for its stunning beauty and figuring. The different colors and textures of Koa wood are determined by the tree’s age, the kind of soil, and elevation that the tree grows in. Koa hues range from light golden blonde, to deep auburn red, to dark chocolate brown. Not all Koa is created equal, the highest quality Koa is curly, tigerstripe and fiddleback Koa. These woods have high figuring and chatoyancy.
Chatoyancy is a property that is usually attributed to gems, the cat’s eye effect or shimmer, which gives a sense of depth in the gem. This property can also be used to describe some of the more dramatic pieces of curly, tigerstripe and fiddleback Koa. This figuring gives the wood a three dimensional quality; and depending on the angle the wood is viewed from, it can take on several completely different characters.
Only a very small fraction cut and collected Koa wood goes to instrument making. Most goes to furniture and hardwood floors. A good luthier can made a small amount of Koa go a long way.