Mahogany is generally heavier than elm wood. This difference in weight is primarily due to the specific gravity of the two woods. Mahogany has a specific gravity of approximately 0.65 to 0.75, while elm wood has a specific gravity of around 0.60 to 0.65. Specific gravity is a measure of the density of a material relative to water, and it is a good indicator of weight. Since mahogany has a higher specific gravity, it is heavier than elm wood. This information is supported by data from the United States Department of Agriculture Forest Service, which provides detailed information on the properties of various woods. The higher specific gravity of mahogany means that it is denser and heavier per unit volume compared to elm wood, making it a heavier material.