The density of wood varies from as low as 6.86 lbs./cubic feet to as high as 78 lbs./cubic ft. Wood types come with different densities based on their moisture content and material. Age, height, growing conditions and radial growth are also factors that can affect wood density.
Some common examples of wood with a density of 50 lb./cubic feet or higher include Boxwood, Ebony, Cocobolo, Greenhart and Grenadilla. Woods, such as Balsa, Alder, Basswood, Buckeye, Cedar and Cottonwood feature much lower densities, ranging 25 lb./cubic feet and below.
Wood is often generally categorize into two groups based on their density, softwood and hardwood. However, this generalization can be a little misleading because softwood is not exactly soft and not all hard wood is hard
Hardwood refers to angiosperms, trees that produce seeds with some type of covering around it, such as a hickory nut or acorn. Soft wood trees, on the other hand, produce seeds with no protection, such as firs and pines.
Softwood accounts for close to 70 percent of the timber used. That is because softwood is more affordable and easier to work. Hardwood however offer better resistance to fire and are the preferred option for high-quality furniture construction.