* "Stone" is a very broad term. It includes many different types of rock, each with its own properties.

* Temperature is relative. The *feeling* of coldness depends on factors like:

* The material's thermal conductivity: How quickly it conducts heat away from your hand.

* The surrounding temperature: A material will feel colder if the air is cold.

Here's what we *can* say about the three materials:

* Granite and marble are both metamorphic rocks. They can feel cool to the touch, but this is more due to their thermal conductivity than a specific temperature.

* "Stone" could include a wide range of materials. Some stones, like limestone or sandstone, might be less dense and feel warmer than granite or marble.

In conclusion: It's impossible to definitively say which is "coldest" without knowing the specific types of granite, marble, and stone you're comparing. They all have the potential to feel cool, but the actual temperature will depend on the surrounding environment.