Mahogany is generally considered more durable than rosewood. This conclusion is based on several factors, including the wood's density, hardness, and resistance to decay and insects.

Mahogany, scientifically known as Swietenia macrophylla, is a dense and heavy wood with a high Janka hardness rating. The Janka hardness test measures the force required to embed a .444-inch steel ball to half its diameter into the wood. Mahogany typically scores between 2,200 and 2,800 lbf (pounds-force), making it one of the hardest woods used in furniture making. This high hardness contributes to its durability, as it resists wear and tear better than softer woods like rosewood.

Rosewood, on the other hand, is a term that encompasses several species of tropical hardwoods, such as Dalbergia spp. While rosewood is also dense and heavy, it generally has a lower Janka hardness rating compared to mahogany. Rosewood species typically range from 1,000 to 2,200 lbf, which is lower than mahogany's range. This lower hardness makes rosewood more susceptible to dents, scratches, and wear over time.

In addition to hardness, the resistance to decay and insects is another important factor in determining durability. Mahogany is known for its resistance to termites and decay, which is partly due to its high oil content. These oils act as natural preservatives, protecting the wood from harmful organisms. Rosewood also has a certain level of resistance to insects and decay, but it is generally less effective than mahogany.

Data from the Wood Database supports these claims. According to their records, the Janka hardness of African mahogany is around 2,400 lbf, while Indian rosewood ranges from 1,200 to 1,800 lbf. Furthermore, the American Hardwood Export Council (AHEC) states that mahogany is highly resistant to termites and decay, making it a suitable choice for outdoor furniture and construction.

In conclusion, mahogany is more durable than rosewood due to its higher hardness, greater resistance to insects and decay, and natural oils that protect the wood. These factors make mahogany a preferred choice for high-quality furniture and construction projects where durability is a priority.