Kauri gum is the resin of the kauri, Agathis australis, a conifer of the family Araucariaceae that grows mostly north of latitude 38° south in the North Island of New Zealand and is the country's largest tree by volume, standing up to fifty metres. Resin seeps from cracks in the bark or from forked and damaged branches and hardens in the air; lumps that fall are buried under soil and leaf litter and slowly fossilise, so that most kauri gum is a subfossil copal a few thousand years old. It ranges from chalky white through red-brown to black, and hard, translucent pale gold gum was prized most. Māori, who called it kapia, chewed the fresh gum, used it to light fires and, bound in flax, as torches, and burned it with animal fat to make the dark pigment for moko tattooing. From the 1840s it was exported for varnish, by the 1890s it was in most English oil varnishes, and later it went into linoleum. Gum-diggers worked the old forest lands of Northland, Coromandel and Auckland, and gum was Auckland's main export in the second half of the nineteenth century. Over nine-tenths of the kauri forest was logged or burnt between 1820 and 1900. Some Te Tai Tokerau Māori traditions see kauri trees as the legs of Tāne Mahuta, god of the forest, holding sky and earth apart.