The better choice between rosewood and purple檀 largely depends on the specific application and personal preference. Rosewood, known for its rich color and distinctive grain, is often favored for its aesthetic appeal and durability. It is highly valued in furniture making and musical instruments due to its strength and resistance to warping. On the other hand, purple檀, also known as sandalwood, is prized for its aromatic scent and is commonly used in traditional Chinese medicine and incense production. While both woods have their unique qualities, rosewood is generally considered superior for furniture and musical instruments due to its superior strength and longevity.

Rosewood is classified as a hardwood, which means it is denser and harder than purple檀. This makes it more resistant to wear and tear, making it an ideal choice for furniture that requires long-term durability. According to the Forest Products Laboratory of the United States Department of Agriculture, the modulus of rupture for rosewood is approximately 3,000 MPa, which is significantly higher than that of purple檀, which is around 1,800 MPa. This indicates that rosewood is more capable of withstanding tension and is less likely to crack or split over time.

Furthermore, rosewood has a higher bending strength, which is crucial for furniture that needs to support heavy loads. The bending strength of rosewood is around 1,100 MPa, whereas purple檀's bending strength is approximately 700 MPa. This difference in bending strength is a significant factor in determining the structural integrity of furniture made from either wood.

In terms of aesthetic value, rosewood's rich color and distinctive grain patterns are highly sought after. It is available in a variety of shades, from dark red to a deep purplish-brown, and its grain can range from straight to highly figured. This versatility makes rosewood a popular choice for high-end furniture and decorative items. In contrast, purple檀 is known for its aromatic scent and is often used in traditional Chinese medicine and incense production. While it has a pleasant smell, it lacks the visual appeal of rosewood.

Another factor to consider is the environmental impact of using these woods. Rosewood is a protected species under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which means that its trade is strictly regulated to prevent overharvesting. This has led to an increase in the price of rosewood and has made it less accessible for some applications. Purple檀, while also a protected species, is less regulated and may be more readily available. However, the demand for purple檀 has also led to concerns about sustainable harvesting practices.

In conclusion, rosewood is generally considered better than purple檀 for furniture and musical instruments due to its superior strength, durability, and aesthetic appeal. While purple檀 has its own unique qualities, such as its aromatic scent, rosewood's combination of physical properties and visual characteristics make it the preferred choice for many applications.