The key distinction between sapphire glass and ordinary transparent glass is in their composition. Sapphire is not a natural gemstone, but a synthetic single-crystal aluminium oxide with a Mohs hardness of 9, second only to diamond. However, the hardness of ordinary glass typically ranges from 5 to 6 on the Mohs scale. This means that sapphire glass is far superior to ordinary glass in terms of scratch resistance and is less likely to leave scratches during daily use. However, it should be noted that ordinary glass also has certain advantages in terms of cost and optical properties. Therefore, the choice between the two materials is actually a question of balancing durability, light transmittance and cost.

Sapphire glass is characterized by its high hardness, which is attributable to its crystal structure. Alumina crystallizes at high temperatures to form a corundum structure, with closely arranged atoms and strong bond energy, making it difficult for foreign substances to cause scratches on its surface. Conversely, ordinary glass is an amorphous material with disordered atomic arrangement inside and relatively low hardness. Sapphire is more fragile and is more likely to crack under severe compact, while ordinary glass may only develop cracks when subjected to an equivalent impact. In terms of optics, the visible light transmittance of sapphire typically exceeds 85%, while that of high-quality ordinary glass can surpass 90%. Additionally, the refractive index of ordinary glass is lower than that of sapphire.

In the watchmaking industry, sapphire glass is frequently used in high-end models. It is particularly suitable for applications where a long-lasting lustrous appearance is required, such as in luxury watches or professional tool watches, while ordinary glass is predominantly used in mid-low end products or designs where cost is a sensitive issue. In the field of custom processing, sapphire glass is much more difficult to process than ordinary glass. Due to its high hardness, diamond tools are required for cutting and polishing, which directly increases the cost. Therefore, when making a choice, users should clearly define their core needs. If they prioritize scratch resistance and long-term beauty, sapphire is the better choice. If they place more importance on economy and a certain degree of impact resistance, ordinary glass might be more suitable.

Sapphire glass is most commonly used in luxury mechanical and diving watches and pilot watches. In such scenarios, the device frequently comes into contact with hard surfaces, which can result in scratches that significantly impact the visual experience. Ordinary glass is more commonly used in fashionable watches or smartwatches. These products are updated regularly, so users may focus more on the overall design than on long-term durability. Additionally, the high hardness of sapphire makes it a popular choice for use in optical windows, such as high-end camera lens protectors or scientific instrument windows, where the surface must also be resistant to abrasion. Overall, it is possible to make reasonable judgments based on usage environment by understanding the physical properties and processing costs of the two materials.