Katalox (Swartzia spp.), also known as Mexican Royal Ebony, has dark reddish-brown to nearly black heartwood, sometimes with a strong purple shade, and sapwood that is clearly marked by a pale yellowish-white color. Katalox is extremely dense, making it somewhat difficult to work. Typically straight grained, the grain can be irregular or interlocked. Native to Southern Mexico, Central America, and northern South America.