Lignum vitae is a hardwood species, known by its botanical name Guaiacum officinale and related species (Zygophyllaceae). The heartwood of this timber is typically dark greenish-brown or nearly black, with a strongly interlocked, irregular grain and a very fine texture. Its unique waxy feel is due to the fact that around 30% of its weight is guaiac gum. The sapwood is clearly demarcated from the heartwood, and is pale yellow or cream in colour.