Peach wood is generally harder than sandalwood. This conclusion is based on the Janka hardness scale, which measures the resistance of wood to indentation. Peach wood typically has a Janka hardness rating of around 1,200 pounds per square inch (psi), while sandalwood generally ranges from 1,050 to 1,200 psi. Despite the close range, peach wood is still considered slightly harder due to its denser grain structure and higher weight.

The hardness of wood is influenced by several factors, including the wood's cellular structure, density, and moisture content. Peach wood, derived from the peach tree, has a dense and interlocked grain pattern, which contributes to its higher hardness. This grain structure makes peach wood more resistant to wear and tear, making it suitable for furniture and flooring applications.

Sandalwood, on the other hand, is known for its aromatic properties and has been used in traditional medicine and incense. While it is also relatively hard, its hardness is not as consistent as peach wood due to variations in its growth conditions and species. The hardness of sandalwood can vary significantly, with some varieties being softer than others.

In summary, peach wood is generally harder than sandalwood, primarily due to its denser grain structure and higher Janka hardness rating. This makes peach wood a more durable option for certain applications, while sandalwood's unique aromatic qualities make it valuable for other uses.