Glass is generally harder to drill than ceramic. This is due to the differences in their hardness and composition. Glass has a Mohs hardness of around 5.5 to 6.5, while ceramic materials can range from 7 to 9 on the same scale. The higher the Mohs hardness, the harder the material is to drill. Ceramics, especially those with a hardness of 7 to 9, are significantly more resistant to drilling than glass.

The hardness of glass is influenced by its amorphous structure, which lacks a regular, repeating pattern of atoms. This structure makes it more brittle and less resistant to penetration. On the other hand, ceramics are crystalline materials with a highly ordered atomic structure, which contributes to their higher hardness and durability. The crystalline structure of ceramics allows for a more uniform distribution of stress, making them more resistant to drilling and other forms of mechanical wear.

Data from the Mohs hardness scale supports this analysis. The Mohs scale is a qualitative measure of mineral hardness, with diamond being the hardest at 10 and talc being the softest at 1. Glass falls between quartz (7) and feldspar (6), while ceramics can range from 7 (like quartz) to 9 (like corundum). This indicates that ceramics are generally harder than glass, making them more challenging to drill.

In practical terms, drilling glass often requires specialized equipment and techniques to prevent cracking or shattering. For example, using a diamond-tipped drill bit and applying low pressure and slow speed can help minimize damage. In contrast, drilling ceramics typically requires even more specialized tools and methods, such as high-speed diamond or carbide-tipped drill bits, and often involves the use of coolant to dissipate heat and reduce wear on the drill bit.

In summary, ceramic materials are generally harder to drill than glass due to their higher Mohs hardness and crystalline structure. This difference in hardness necessitates the use of specialized equipment and techniques when drilling these materials.