* Hardness is complex: Hardness of rocks is measured by various scales (like Mohs hardness), but these scales focus on individual minerals. Rocks are made of multiple minerals, so their overall hardness is less straightforward.

* Gneiss and Granite: Different textures:

* Gneiss: A metamorphic rock, meaning it's formed from other rocks under heat and pressure. This process gives it a distinct banding or layering.

* Granite: An igneous rock, meaning it cooled from molten magma. It tends to have a more even, granular texture.

* Variations within each type: Both gneiss and granite have a range of compositions, which impacts their hardness.

In general:

* Gneiss can be harder: The metamorphic process in gneiss can create very strong mineral alignments, which can result in a harder overall rock.

* Granite can be harder: Some granites contain particularly hard minerals, which can make them harder than some types of gneiss.

Conclusion:

It's impossible to say definitively which is "harder" without specifying the exact composition of the gneiss and granite samples you're comparing.