Woods that are so hard and dense that they are virtually impossible to hammer a nail into, and that do not float in water, are colloquially referred to as "ironwood". Several types of wood compete for the distinction of being the hardest wood on the planet. While some sources state that the dark Bongossi tree is the hardest wood in the world, other sources give that title to the pockwood of the guaiac tree.
Bongossi - tropical deciduous tree
Bongossi is known as "Red Ironwood" in English-speaking countries. In fact, it is a tropical wood species with an extremely high density. It reaches a record amount of 1.10 and 1.20 g / cm³. By comparison, oak, the hardest indigenous wood, has a density of 0.67 to 0.70 g / cm³. Bongossi is a deciduous tree that grows in the tropical rainforests of Africa. The hardwood has a dark, red-brown colour and is extremely weather-resistant. The wood doesn’t float due to the high density. In water, it sinks like a stone. Hammering a nail into it is only possible with a borehole. Like teak wood, the high oil content of the wood acts as a natural protection mechanism.
Guaiac Tree Pockwood
Pockwood from the Guaiac tree has a density of about 1.2g / cm³ and rivals Bongossi as the hardest wood in the world. The evergreen tree grows in the subtropical and tropical regions of the American continent and is especially prevalent in the Amazon rainforest. The wood is very rich in resin and was used for shipbuilding centuries ago because of its resistance to external influences. One special feature is the set of self-lubricating properties of this type of wood. Even bearings and shafts can be made from tropical hardwood. Since the guaiac tree is threatened by centuries of decimation of its population, the international trade in hardwood is subject to approval.
Ipe Wood from the lapacho Tree
Ipe is the name of a wood that comes from several species of the lapacho tree. With an average density of 1.2 g / cm³, Ipe competes for the title of "Hardest Wood in the World" with the two aforementioned types of wood. Lapacho trees are common in Central and South America. The inner bark is used for tea production. This tradition goes back to the Incas. Ipe wood has similar properties to teak when it comes to splintering risk and dimensional stability. The wood colour varies from brown to olive. Due to intensive forest management in Latin America and the associated decline in tree populations, some Southern and Central American states have endowed lapacho trees with species protection. However, there is no international agreement regulating trade in Ipe wood.