Mahogany is generally more susceptible to cracking than Ebony. This is due to several factors that affect the wood's durability and resistance to environmental changes.

Mahogany has a higher moisture content and lower density compared to Ebony. These characteristics make it more prone to expansion and contraction with changes in humidity and temperature. According to a study by the Forest Products Laboratory (FPL), Mahogany has a moisture content of around 10-12% and a density of about 0.57-0.62 g/cm³, whereas Ebony has a moisture content of 8-10% and a density of approximately 0.93-1.05 g/cm³. The higher moisture content in Mahogany means it absorbs and releases more moisture, leading to greater movement and potential for cracking.

Additionally, the grain structure of Mahogany is more open and less dense than that of Ebony. This allows moisture to penetrate deeper into the wood, increasing the risk of cracking. Ebony, on the other hand, has a very tight grain and high density, which makes it more resistant to moisture absorption and movement.

Furthermore, the chemical composition of the wood also plays a role. Mahogany contains more tannins than Ebony, which can contribute to the wood's brittleness and susceptibility to cracking. Tannins are organic compounds that can make wood more prone to cracking and warping when exposed to moisture.

In conclusion, Mahogany is more susceptible to cracking than Ebony due to its higher moisture content, lower density, open grain structure, and higher tannin content. These factors make Mahogany more vulnerable to environmental changes and potential cracking, while Ebony's denser, tighter grain and lower moisture content provide greater stability and resistance to cracking.