Color can be highly variable, but tends to be medium golden or reddish brown, similar to koa or mahogany. There are usually contrasting bands of color in the growth rings, and it is not uncommon to see boards with ribbon-like streaks of color. Boards figured with wavy and/or curly grain are also not uncommon. Grain is usually straight to slightly interlocked, and sometimes wavy. Uniform fine to medium texture. Although called ‘blackwood,’ the name is somewhat of a misnomer, as its wood is not really black. Rather, its lustrous golden brown grain has been used as a sustainable alternative to the closely related koa (Acacia koa). The species has been introduced to a number of regions worldwide—either as an ornamental shade tree, or on a plantation for lumber—and in many areas, the hardy trees have become an invasive species. Australian blackwood is very closely related to koa, a species endemic to the island of Hawaii. Acacia melanoxylon is believed to be the ancestral source of both A. koa, and also highland tamarind (Acacia heterophylla)—another island species—endemic to Reunion island. On a practical level, the wood of Australian blackwood tends to have a straighter grain, and slightly better machining characteristics when compared to koa. However, while pieces of koa with dramatic coloration and figured or wild grain tend to be more commonplace, on the whole, the two species are virtually indistinguishable.
