While the grains in granite are tightly interlocked, there are microscopic spaces between them. These spaces are filled with air or water. The size and distribution of these gaps contribute to the porosity of granite, which can range from 0.1 to 1%.

Here's why this is important:

* Water absorption: The presence of these gaps allows granite to absorb water, which can affect its durability and stain resistance.

* Weathering: Water can seep into these gaps and freeze, expanding and causing the granite to crack over time.

* Polishing: When granite is polished, the gaps between the grains are filled with a resin or sealant to improve its appearance and durability.

It's important to note that the presence of these gaps does not make granite weak or unreliable. In fact, the tightly interlocking nature of the grains makes granite one of the most durable natural stones. However, it's important to be aware of the potential for water absorption and weathering when using granite in construction and design.