While some diorites can have larger crystals, they are not typically classified as coarse-grained. The grain size in diorite is usually between 1 and 5 millimeters. This makes it fall somewhere between fine-grained (less than 1 mm) and coarse-grained (greater than 5 mm).

Here's a quick breakdown:

* Fine-grained: Crystals are too small to be seen with the naked eye (e.g., basalt)

* Medium-grained: Crystals are easily visible with the naked eye (e.g., diorite)

* Coarse-grained: Crystals are larger than 5 mm (e.g., granite)

Keep in mind that there can be variations within rock types, and some diorites might have grains bordering on the coarse-grained range.